Latex binders, aqueous coatings and paints having freeze-thaw stability and methods for using same

ABSTRACT

Disclosed are latex polymers and an aqueous coating compositions having excellent freeze-thaw stability, open time, stain resistance, low temperature film formation, foam resistance, block resistance, adhesion, water sensitivity and a low-VOC content. The latex polymers and aqueous coating compositions include at least one latex polymer derived from at least one monomer copolymerized or blended with an alkoxylated compound, for example an alkoxylated tristyrylphenol or an alkoxylated tributylphenol. Also provided is an aqueous coating composition including at least one latex polymer, at least one pigment, water and at least one freeze-thaw additive. Typically, the freeze-thaw additive in an amount greater than about 1.3% by weight of the polymer, typically in an amount greater than about 2% by weight of the polymer, in an amount greater than about 4% by weight of the polymer, in an amount greater than about 7.5% by weight of the polymer, in an amount greater than about 10% by weight of the polymer or in an amount greater than about 20% by weight of the polymer.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application Ser.No. 61/022,206, filed Jan. 18, 2008, U.S. Provisional Application Ser.No. 61/022,443, filed Jan. 21, 2008 and U.S. Provisional ApplicationSer. No. 61/199,936, filed Nov. 21, 2008, all herein incorporated byreference

FIELD OF THE INVENTION

The present invention relates to the use of a particular family ofalkoxylated compounds, e.g alkoxylated tristyrylphenol and alkoxylatedtributylphenol, for improving freeze-thaw stability and open time ofaqueous coating compositions such as paint and paper coatingcompositions. In particular, the present invention relates to the use ofcertain reactive alkoxylated compound based monomers, surface activealkoxylated compound surfactants, and surface active alkoxylatedcompound additives for freeze-thaw stability of aqueous latexdispersions, aqueous latex binders and aqueous latex paints.

BACKGROUND OF THE INVENTION

Latex paints are used for a variety of applications including interiorand exterior, and flat, semi-gloss and gloss applications. However,paints and aqueous latex dispersions, particularly low VOC paints andlatex dispersions, suffer from a lack of freeze-thaw stability. This isparticularly a problem during transportation and storage.

Latex freeze-thaw (sometimes herein referred to as “F/T”) stability,including the freezing-thawing process, destabilization mechanism, andpolymer structures, have been extensively studied since 1950. Blackley,D. C., Polymer Lattices—Science and Technology, 2^(nd) Ed., Vol. 1,Chapman & Hall, 1997, gives a comprehensive review of colloidaldestabilization of latexes by freezing. The freezing process starts withthe decrease of temperature which leads to the formation of icecrystals. The ice crystal structures progressively increase the latexparticle concentration in the unfrozen water. Eventually latex particlesare forced into contact with each other at the pressure of growing icecrystal structures, resulting in particle aggregation or interparticlecoalescence. To make a stable latex dispersion in aqueous medium orlatex paints with freeze-thaw stability, various approaches have beenemployed. The addition of antifreeze agents, e.g. glycol derivatives,has been applied to latex paint to achieve freeze-thaw stability. Thus,latex paints include anti-freeze agents to allow the paints to be usedeven after they have been subjected to freezing conditions. Exemplaryanti-freeze agents include ethylene glycol, diethylene glycol andpropylene glycol.

See, Bosen, S. F., Bowles, W. A., Ford, E. A., and Person, B. D.,“Antifreezes,” Ullmann's Encyclopedia of Industrial Chemistry, 5^(th)Ed., Vol. A3, VCH Verlag, pages 23-32, 1985. However, a low or no VOCrequirement means the glycol level that can be used has to be reduced oreliminated. Aslamazova, T. R., Colloid Journal, Vol. 61, No. 3, 1999,pp. 268-273, studied the freeze resistance of acrylate latexes andrevealed the role of electrostatic contribution to the potential energyof latex particle interactions. Using electrostatic effects on colloidalsurface, the interactions of Coulombic repulsion between the chargedlatex particles lead to higher potential energy. The electrical effectsstabilize the latex particles in the freezing and thawing process.

Rajeev Farwaha et. al. (U.S. Pat. No. 5,399,617) discloses thecopolymerizable amphoteric surfactants and discloses latex copolymerscomprising the copolymerizable amphoteric surfactants impart freeze-thawstability to the latex paints.

Cheng-Le Zhao et. al. (U.S. Pat. No. 6,933,415 B2) discloses latexpolymers including polymerizable alkoxylated surfactants and disclosesthe low VOC aqueous coatings have excellent freeze-thaw stability.

Rajeev Farwaha et. al. (U.S. Pat. No. 5,610,225) discloses incorporatinga monomer with long polyethylene glycol structures to achieve stablefreeze-thaw latex.

Masayoshi Okubo et. al. (U.S. Pat. No. 6,410,655 B2) disclosesfreeze-thaw stability of latex polymers including ethylenic unsaturatedmonomers.

The additives used as anti-freeze agents are effective for theirpurposes but are becoming more and more undesirable because they arevolatile organic compounds (VOC's). After application of the latex paintto a substrate, the VOC's slowly evaporate into the surroundings.

With strict environmental legislation requiring the reduction of theamount of Volatile Organic Compounds (VOC) in coatings, it is desirableto have paint formulations without or with substantially reduced VOCcontent, which would include coalescing agents and freeze-thaw agents,among others. Latex binder manufactures are thus forced to develop lowVOC binders to meet the requirements of paints and coatings industry.However, low VOC coatings and paints must meet or exceed coatingperformance standards set in the industry.

In traditional latex binders for architectural coatings, the glasstransition temperature is between above 10° C. to about 40° C. However,such architectural coatings often need and contain coalescent agents tosoften such latex binders (i.e., soften the latex binders havingrelatively Tg in the range of above 10° C. to about 40° C.) oranti-freeze agents; both of which are typically high VOC solvents. Thus,these traditional architectural coatings with higher Tg latex binderscannot be formulated to be low VOC without solvents.

For the low VOC application (i.e., low Tg) binders, the average Tg isclose to or below 0° C. However, the latex binder with low Tg causesgrit when subjected to freeze/thaw cycles as well as exposure tomechanical shear. The resulting coating films are softer and tackier,even after fully dried, and are susceptible to blocking and dirt pick-upeffects. Also, such low Tg latex binders and resulting latex paints arenot stable, and gel in a cold environmental storage or transportationprocess. Freeze-Thaw stability of low Tg latex binders and low VOCpaints is critically important for transportation, storage, andpractical applications. Thus, there is a need to develop latex paintsand latex particle dispersions using emulsion polymer technology whichmeet zero or low VOC requirement and at the same provide excellentmechanical and film performance without sacrificing the freeze-thawstability of those paints.

SUMMARY OF THE INVENTION

The present invention relates to the use of a particular family ofalkoxylated compounds with bulky hydrophobic groups, e.g., alkoxylatedtristyrylphenols or alkoxylated tributylphenols, for improvingfreeze-thaw stability, as well as other properties such as open time,low temperature film formation, stain resistance, film gloss,dispersibility, hiding and scrub resistance, foam resistance, blockresistance, adhesion and water sensitivity, among others, of latexbinders, paints and coatings. During the thawing process of thefreeze-thaw process in latex dispersions and paint formulation, it isbelieved that the latex particles with high Tg are easy to recover,while the particles with relatively low Tg can not recover from theaggregation or coalescence states which gel.

While not being bound to theory, it is theorized the present inventionin part stabilizes the latex particles using steric effects of largerhydrophobic groups to form a protective layer on the surfaces of softlatex particles. The large hydrophobic groups adsorbed or grafted ontothe latex particles or co-polymerized into the latex particles preventthese latex particles from approaching the surfaces of other soft latexparticles and increase the distance of separation between soft latexparticles. The alkylene, e.g., ethylene oxide units from the surfactantof the alkoxylated compounds chains also form a layer which interactswith aqueous medium.

In accordance with the invention, aqueous coating compositions (e.g.latex paints, latex dispersion) including an alkoxylated compound can beproduced having excellent freeze-thaw stabilities with the addition oflittle or no other anti-freeze agents such as glycol, coalescents andhigh VOC components, more typically with no anti-freeze agents.Freeze-thaw stability or being freeze-thaw stable generally isunderstood to mean that the composition/formulation does not gel in 3 ormore F/T cycles, typically 5 or more F/T cycles.

The alkoxylated compounds can be employed in a number of ways forimproving freeze-thaw stability of latex binders, paints and coatings.The present invention may employ polymerizable reactive alkoxylatedmonomers as a reactant during emulsion polymerization to form the latexpolymer. The present invention may employ one or more surface activealkoxylated compounds described herein as a surfactant (emulsifier)during emulsion polymerization to form the latex polymer. The presentinvention may employ a surface active alkoxylated compound as anadditive to a latex polymer-containing aqueous dispersion orconcentrate.

In one aspect, the present invention is a latex polymer derived from atleast one first monomer and at least one polymerizable reactivealkoxylated second monomer having the structural formula IA:

wherein R1, R2 and R3 are independently selected from:

—H, tert-butyl, butyl, isobutyl,

wherein X is a divalent hydrocarbon radical selected from linear orbranched alkylene radicals having from 2 to 8 carbon atoms; wherein n isan integer of from 1 to 100, wherein R comprises an ethylenicallyunsaturated group. In one embodiment, R can be acrylate, C₁-C₆ alkylacrylate, allyl, vinyl, maleate, itaconate or fumarate. R can also beselected from acrylo, methacrylo, acrylamido, methacrylamido,diallylamino, allyl ether, vinyl ether, α-alkenyl, maleimido, styrenyl,and/or α-alkyl styrenyl groups.

In another embodiment, R has a chemical structure: R^(a)CH═C(R^(b))COO—,wherein if R^(a) is H, then R^(b) is H, C₁-C₄ alkyl, or —CH₂COOX; ifR^(a) is —C(O)OX, then R^(b) is H or —CH₂C(O)OX^(a); or if R^(a) is CH₃,then R^(b) is H and X^(a) is H or C₁-C₄ alkyl. R can, in anotherembodiment, have chemical structure: —HC═CYZ or —OCH═CYZ, wherein Y isH, CH₃, or Cl; Z is CN, Cl, —COOR^(c), —C₆H₄R^(c), —COOR^(d), or—HC═CH₂; R^(d) is C₁-C₈ alkyl or C₂-C₈ hydroxy alkyl; R^(c) is H, Cl,Br, or C₁-C₄ alkyl.

In another aspect, the present invention is a latex polymer derived fromat least one first monomer and at least one second monomer having thestructural formula IB:

wherein n is an integer of from about 1 to about 100, and R₄ is selectedfrom H and C₁-C₆ alkyl. In one embodiment, n is an integer of from about3 to about 80, typically, about 10 to about 60, and more typically fromabout 20 to about 50. The at least one first monomer can, in oneembodiment, comprise at least one acrylic monomer selected from thegroup consisting of acrylic acid, acrylic acid esters, methacrylic acid,and methacrylic acid esters. In another embodiment, the latex polymercan be derived from one or more monomers selected from styrene,alpha-methyl styrene, vinyl chloride, acrylonitrile, methacrylonitrile,ureido methacrylate, vinyl acetate, vinyl esters of branched tertiarymonocarboxylic acids, itaconic acid, crotonic acid, maleic acid, fumaricacid, ethylene, or C₄-C₈ conjugated dienes.

In another embodiment, the composition of the present invention isfreeze-thaw stable and the polymer has a glass transition temperature(Tg) of between about −15° C. and about 15° C., typically about −15° C.and about 12° C., more typically between about −5° C. and about 5° C.,and even more typically between about −5° C. and about 0° C.

In another embodiment, the polymer of the present invention has a meanparticle size (sometimes referred to as mean particle diameter, D₅₀) ofless than about 200 nm, more typically a mean particle size of less thanabout 190 nm, and most typically a mean particle size of less than about175 nm.

In a further embodiment, the composition of the present invention isfreeze-thaw stable, and the polymer can have a Tg of between about −15°C. and about 12° C. and a mean particle size of less than about 200 nm,or a Tg of between about −5° C. and about 5° C. and a mean particle sizeof less than about 200 nm, or a Tg of between about −5° C. and about 0°C. and a mean particle size of less than about 200 nm, or a Tg ofbetween about −15° C. and about 12° C. and a mean particle size of lessthan about 190 nm, or a Tg of between about −5° C. and about 5° C. and amean particle size of less than about 190 nm, or a Tg of between about−5° C. and about 0° C. and a mean particle size of less than about 190nm, or a Tg of between about −15° C. and about 12° C. and a meanparticle size of less than about 175 nm, or a Tg of between about −5° C.and about 5° C. and a mean particle size of less than about 175 nm, or aTg of between about −5° C. and about 0° C. and a mean particle size ofless than about 175 nm.

In another aspect, the present invention is a latex coating compositioncomprising: (a) a latex polymer as described above or as describedanywhere herein; and (b) water. It is understood that the latex coatingcomposition can contain other additive/ingredients including but notlimited to biocides, surfactants, pigments, dispersants, etc. The latexcoating composition can further comprise a freeze-thaw additivecomprising an ethoxylated tristyrylphenol having the structural formulaIC:

wherein, n is an integer of from 1 to 100, wherein R₅ is —OH, —OCH₃,—OC₂H₅, —OC₃H₇, —OC₄H₉, —OC₅H₁₁, —OC₆H₁₃, —Cl, —Br, —CN, Phosphonate(—PO₃ ⁻M⁺), Phosphate (PO₄ ⁻M⁺), Sulfate (SO₄ ⁻M⁺), Sulfonate (SO₃ ⁻M⁺),carboxylate (COO⁻M⁺), a nonionic group, or a quaternary ammonium ion,wherein M+ is a cation including but not limited to H⁺, Na⁺, NH₄ ⁺, K⁺or Li⁺. In one embodiment, n is an integer of from about 1 to 40.

In one embodiment, the latex coating composition contains a freeze-thawadditive in an amount effective to impart freeze-thaw stability to thecomposition. In one embodiment, the effective amount is greater thanabout 1.3% by weight of the polymer, typically in an amount greater thanabout 1.6% by weight of the polymer. In another embodiment, the latexcoating composition contains a freeze-thaw additive in an amount greaterthan about 2% by weight of the polymer, typically in an amount greaterthan about 4% by weight of the polymer. In another embodiment, the latexcoating composition contains a freeze-thaw additive in an amount greaterthan about 7.5% by weight of the polymer, typically in an amount greaterthan about 8% by weight of the polymer. In yet another embodiment, thelatex coating composition contains a freeze-thaw additive in an amountgreater than about 10% by weight of the polymer. In yet anotherembodiment, the latex coating composition contains a freeze-thawadditive in an amount greater than about 20% by weight of the polymer.In another embodiment, the latex coating composition contains afreeze-thaw additive in an amount between about 1.6% and 7.5% by weightof the polymer.

In one embodiment, the aforementioned latex coating composition isfreeze-thaw stable and the latex polymer comprises a glass transitiontemperature (Tg) of between about −20° C. and about 12° C., typicallybetween about −5° C. and about 5° C., more typically between about −5°C. and about 0° C. In another embodiment, a latex polymer in theaforementioned latex coating has a mean particle size of less than about200 nm, more typically less than about 190 nm, most typically, less thanabout 175.

In yet another aspect, the present invention is a method of preparing alatex polymer, comprising copolymerizing (1) at least one first monomerwith (2) at least one second monomer, the second monomer a polymerizablereactive tristyrylphenol having the structural formula IA:

wherein R1, R2 and R3 are independently selected from:

—H, tert-butyl, butyl, isobutyl,

wherein X is a divalent hydrocarbon radical selected from linear orbranched alkylene radicals having from 2 to 8 carbon atoms; wherein n isin the range of 1-100, wherein R is an ethylenically unsaturated groupincluding but not limited to acrylate, C₁-C₆ alkyl acrylate, allyl,vinyl, maleate, itaconate or fumarate. R can also be selected fromacrylo, methacrylo, acrylamido, methacrylamido, diallylamino, allylether, vinyl ether, α-alkenyl, maleimido, styrenyl, and/or α-alkylstyrenyl groups.

In a further aspect, the present invention is a method of preparinglatex polymer, comprising copolymerizing (1) at least one latex monomerwith (2) at least one polymerizable reactive tristyrylphenol having thestructural formula IB:

wherein n is an integer of from 1 to 100, and R₄ is selected from H andC₁-C₁₀ alkyl, typically C₁-C₆ alkyl.

In one embodiment, in one or both of the aforementioned methods, anaqueous dispersion of the polymer is freeze-thaw stable, where thepolymer comprises a glass transition temperature (Tg) of between about−20° C. and about 20° C., more typically between about −15° C. and about12° C., most typically between about −5° C. and about 0° C. In anotherembodiment, the polymer utilized in one or more of the above-referencedmethods comprises a mean particle size of less than about 200 nm, moretypically a mean particle size of less than about 190 nm, and mosttypically a mean particle size of less than about 175 nm.

In yet another aspect, the present invention is a method of preparingfreeze-thaw stable latex polymer, comprising copolymerizing (1) at leastone first monomer with (2) at least one second monomer having thestructural formula IB:

wherein n is in the range of 1-100, R₄ is selected from the groupconsisting of H and C₁-C₈ alkyl, and wherein the polymer has a glasstransition temperature (Tg) of between about −15° C. and about 12° C.and a mean particle size of less than about 200 nm, or a Tg of betweenabout −5° C. and about 5° C. and a mean particle size of less than about200 nm, or a Tg of between about −5° C. and about 0° C. and a meanparticle size of less than about 200 nm, or a Tg of between about −15°C. and about 12° C. and a mean particle size of less than about 190 nm,or a Tg of between about −5° C. and about 5° C. and a mean particle sizeof less than about 190 nm, or a Tg of between about −5° C. and about 0°C. and a mean particle size of less than about 190 nm, or a Tg ofbetween about −15° C. and about 12° C. and a mean particle size of lessthan about 175 nm, or a Tg of between about −5° C. and about 5° C. and amean particle size of less than about 175 nm, or a Tg of between about−5° C. and about 0° C. and a mean particle size of less than about 175nm.

In still a further aspect, the present invention is a low VOC latexcoating composition, comprising: (a) at least one latex polymer; (b) atleast one pigment; (c) water; and (d) a freeze-thaw additive in anamount greater than about 1.6% by weight of the polymer; wherein thefreeze thaw additive comprises an ethoxylated tristyrylphenol having thestructural formula IIA:

wherein, n is an integer of from 1 to 100, wherein R is —OH, —OCH₃,—OC₂H₅, —OC₃H₇, —OC₄H₉, —OC₅H₁₁, —OC₆H₁₃, —Cl, —Br, —CN, Phosphonate(—PO₃ ⁻M⁺), Phosphate (PO₄ ⁻M⁺), Sulfate (SO₄ ⁻M⁺), Sulfonate (SO₃ ⁻M⁺),carboxylate (COO⁻M⁺), a nonionic group, or a quaternary ammonium ion,wherein M+ is a cation including but not limited to H⁺, Na⁺, NH₄ ⁺, K⁺or Li⁺. In one embodiment, n is an integer of from about 1 to 40.

In one embodiment, the freeze-thaw additive is present in the latexcoating composition in an amount greater than about 2% by weight of thepolymer. In another embodiment, the freeze-thaw additive is present inan amount greater than about 4% by weight of the polymer. In yet anotherembodiment, the freeze-thaw additive is present in an amount greaterthan about 7.5% by weight of the polymer. In a further embodiment, thefreeze-thaw additive is present in an amount greater than about 20% byweight of the polymer. In still a further embodiment, the freeze-thawadditive is present in an amount between about 1.6% and 7.5% by weightof the polymer.

In one embodiment, the at least one latex monomer in the latex coatingcomposition comprises a glass transition temperature (Tg) of betweenabout −15° C. and about 12° C., typically between about −5° C. and about5° C., more typically between about −5° C. and about 0° C.

In one embodiment, the at least one latex polymer in the latex coatingcomposition comprises has a mean particle size of less than about 200nm, typically less than about 190 nm, and more typically less than about175 nm.

In one embodiment, the latex coating composition is characterized by anopen time of greater than about 2 minutes, an open time of greater thanabout 4 minutes, an open time of greater than about 6 minutes or an opentime of greater than about 12 minutes.

In a further embodiment, the latex coating composition of the presentinvention is freeze-thaw stable, wherein the polymer has a Tg of betweenabout −15° C. and about 12° C. and a mean particle size of less thanabout 200 nm, or a Tg of between about −5° C. and about 5° C. and a meanparticle size of less than about 200 nm, or a Tg of between about −5° C.and about 0° C. and a mean particle size of less than about 200 nm, or aTg of between about −15° C. and about 12° C. and a mean particle size ofless than about 190 nm, or a Tg of between about −5° C. and about 5° C.and a mean particle size of less than about 190 nm, or a Tg of betweenabout −5° C. and about 0° C. and a mean particle size of less than about190 nm, or a Tg of between about −15° C. and about 12° C. and a meanparticle size of less than about 175 nm, or a Tg of between about −5° C.and about 5° C. and a mean particle size of less than about 175 nm, or aTg of between about −5° C. and about 0° C. and a mean particle size ofless than about 175 nm, where the latex coating composition ischaracterized by an open time of greater than about 2 minutes, an opentime of greater than about 4 minutes, an open time of greater than about6 minutes or an open time of greater than about 12 minutes.

In a another embodiment, the latex coating composition of the presentinvention is freeze-thaw stable where the freeze-thaw additive ispresent in the latex coating composition in an effective amount, whichin one embodiment is greater than about 2% by weight of the polymer,where the polymer has a Tg of between about −15° C. and about 12° C. anda mean particle size of less than about 200 nm, or a Tg of between about−5° C. and about 5° C. and a mean particle size of less than about 200nm, or a Tg of between about −5° C. and about 0° C. and a mean particlesize of less than about 200 nm, or a Tg of between about −15° C. andabout 12° C. and a mean particle size of less than about 190 nm, or a Tgof between about −5° C. and about 5° C. and a mean particle size of lessthan about 190 nm, or a Tg of between about −5° C. and about 0° C. and amean particle size of less than about 190 nm, or a Tg of between about−15° C. and about 12° C. and a mean particle size of less than about 175nm, or a Tg of between about −5° C. and about 5° C. and a mean particlesize of less than about 175 nm, or a Tg of between about −5° C. andabout 0° C. and a mean particle size of less than about 175 nm, wherethe latex coating composition is characterized by an open time ofgreater than about 2 minutes, an open time of greater than about 4minutes, an open time of greater than about 6 minutes or an open time ofgreater than about 12 minutes.

In a further embodiment, the latex coating composition of the presentinvention is freeze-thaw stable where the freeze-thaw additive ispresent in the latex coating composition in an amount greater than about4% by weight of the polymer, and where the polymer has a Tg of betweenabout −15° C. and about 12° C. and a mean particle size of less thanabout 200 nm, or a Tg of between about −5° C. and about 5° C. and a meanparticle size of less than about 200 nm, or a Tg of between about −5° C.and about 0° C. and a mean particle size of less than about 200 nm, or aTg of between about −15° C. and about 12° C. and a mean particle size ofless than about 190 nm, or a Tg of between about −5° C. and about 5° C.and a mean particle size of less than about 190 nm, or a Tg of betweenabout −5° C. and about 0° C. and a mean particle size of less than about190 nm, or a Tg of between about −15° C. and about 12° C. and a meanparticle size of less than about 175 nm, or a Tg of between about −5° C.and about 5° C. and a mean particle size of less than about 175 nm, or aTg of between about −5° C. and about 0° C. and a mean particle size ofless than about 175 nm, where the latex coating composition ischaracterized by an open time of greater than about 2 minutes, an opentime of greater than about 4 minutes, an open time of greater than about6 minutes or an open time of greater than about 12 minutes.

In a further embodiment, the latex coating composition of the presentinvention is freeze-thaw stable where the freeze-thaw additive ispresent in the latex coating composition in an amount greater than about7.5% by weight of the polymer, where the polymer has a Tg of betweenabout −15° C. and about 12° C. and a mean particle size of less thanabout 200 nm, or a Tg of between about −5° C. and about 5° C. and a meanparticle size of less than about 200 nm, or a Tg of between about −5° C.and about 0° C. and a mean particle size of less than about 200 nm, or aTg of between about −15° C. and about 12° C. and a mean particle size ofless than about 190 nm, or a Tg of between about −5° C. and about 5° C.and a mean particle size of less than about 190 nm, or a Tg of betweenabout −5° C. and about 0° C. and a mean particle size of less than about190 nm, or a Tg of between about −15° C. and about 12° C. and a meanparticle size of less than about 175 nm, or a Tg of between about −5° C.and about 5° C. and a mean particle size of less than about 175 nm, or aTg of between about −5° C. and about 0° C. and a mean particle size ofless than about 175 nm, where the latex coating composition ischaracterized by an open time of greater than about 2 minutes, an opentime of greater than about 4 minutes, an open time of greater than about6 minutes or an open time of greater than about 12 minutes.

In a further embodiment, the latex coating composition of the presentinvention is freeze-thaw stable where the freeze-thaw additive ispresent in the latex coating composition in an amount greater than about20% by weight of the polymer, where the polymer has a Tg of betweenabout −15° C. and about 12° C. and a mean particle size of less thanabout 200 nm, or a Tg of between about −5° C. and about 5° C. and a meanparticle size of less than about 200 nm, or a Tg of between about −5° C.and about 0° C. and a mean particle size of less than about 200 nm, or aTg of between about −15° C. and about 12° C. and a mean particle size ofless than about 190 nm, or a Tg of between about −5° C. and about 5° C.and a mean particle size of less than about 190 nm, or a Tg of betweenabout −5° C. and about 0° C. and a mean particle size of less than about190 nm, or a Tg of between about −15° C. and about 12° C. and a meanparticle size of less than about 175 nm, or a Tg of between about −5° C.and about 5° C. and a mean particle size of less than about 175 nm, or aTg of between about −5° C. and about 0° C. and a mean particle size ofless than about 175 nm, where the latex coating composition ischaracterized by an open time of greater than about 2 minutes, an opentime of greater than about 4 minutes, an open time of greater than about6 minutes or an open time of greater than about 12 minutes.

In a further embodiment, the latex coating composition of the presentinvention is freeze-thaw stable where the freeze-thaw additive ispresent in the latex coating composition in an amount between about 1.6%and 7.5% by weight of the polymer, where the polymer has a Tg of betweenabout −15° C. and about 12° C. and a mean particle size of less thanabout 200 nm, or a Tg of between about −5° C. and about 5° C. and a meanparticle size of less than about 200 nm, or a Tg of between about −5° C.and about 0° C. and a mean particle size of less than about 200 nm, or aTg of between about −15° C. and about 12° C. and a mean particle size ofless than about 190 nm, or a Tg of between about −5° C. and about 5° C.and a mean particle size of less than about 190 nm, or a Tg of betweenabout −5° C. and about 0° C. and a mean particle size of less than about190 nm, or a Tg of between about −15° C. and about 12° C. and a meanparticle size of less than about 175 nm, or a Tg of between about −5° C.and about 5° C. and a mean particle size of less than about 175 nm, or aTg of between about −5° C. and about 0° C. and a mean particle size ofless than about 175 nm, where the latex coating composition ischaracterized by an open time of greater than about 2 minutes, an opentime of greater than about 4 minutes, an open time of greater than about6 minutes or an open time of greater than about 12 minutes.

In still yet another aspect, the present invention is a latex coatingcomposition, comprising: (a) at least one latex polymer; (b) at leastone pigment; (c) water; and (d) a freeze-thaw additive in an amountgreater than about 1.6% by weight of the polymer; wherein the freezethaw additive comprises an ethoxylated tributylphenol having thestructural formula IIB:

wherein, n is an integer of from 1 to 100, wherein R₅ is —OH, —OCH₃,—OC₂H₅, —OC₃H₇, —OC₄H₉, —OC₅H₁₁, —OC₆H₁₃, —Cl, —Br, —CN, Phosphonate(—PO₃ ⁻M⁺), Phosphate (PO₄ ⁻M⁺), Sulfate (SO₄ ⁻M⁺), Sulfonate (SO₃ ⁻M⁺),carboxylate (COO⁻M⁺), a nonionic group, or a quaternary ammonium ion,wherein M+ is a cation including but not limited to H⁺, Na⁺, NH₄ ⁺, K⁺or Li⁺. In one embodiment, n is an integer of from about 1 to 40.

In one embodiment, the freeze-thaw additive is present in the latexcoating composition in an amount greater than about 2% by weight of thepolymer. In another embodiment, the freeze-thaw additive is present inan amount greater than about 4% by weight of the polymer. In yet anotherembodiment, the freeze-thaw additive is present in an amount greaterthan about 7.5% by weight of the polymer. In a further embodiment, thefreeze-thaw additive is present in an amount greater than about 20% byweight of the polymer. In still a further embodiment, the freeze-thawadditive is present in an amount between about 1.6% and 7.5% by weightof the polymer.

In one embodiment, the at least one latex monomer in the latex coatingcomposition comprises a glass transition temperature (Tg) of betweenabout −15° C. and about 12° C., typically between about −5° C. and about5° C., more typically between about −5° C. and about 0° C.

In one embodiment, the at least one latex monomer in the latex coatingcomposition comprises has a mean particle size of less than about 200nm, typically less than about 190 nm, and more typically less than about175 nm.

In one embodiment, the latex coating composition is characterized by anopen time of greater than about 2 minutes, an open time of greater thanabout 4 minutes, an open time of greater than about 6 minutes or an opentime of greater than about 12 minutes.

In a further embodiment, the latex coating composition of the presentinvention is freeze-thaw stable, wherein the polymer has a Tg of betweenabout −15° C. and about 12° C. and a mean particle size of less thanabout 200 nm, or a Tg of between about −5° C. and about 5° C. and a meanparticle size of less than about 200 nm, or a Tg of between about −5° C.and about 0° C. and a mean particle size of less than about 200 nm, or aTg of between about −15° C. and about 12° C. and a mean particle size ofless than about 190 nm, or a Tg of between about −5° C. and about 5° C.and a mean particle size of less than about 190 nm, or a Tg of betweenabout −5° C. and about 0° C. and a mean particle size of less than about190 nm, or a Tg of between about −15° C. and about 12° C. and a meanparticle size of less than about 175 nm, or a Tg of between about −5° C.and about 5° C. and a mean particle size of less than about 175 nm, or aTg of between about −5° C. and about 0° C. and a mean particle size ofless than about 175 nm, where the latex coating composition ischaracterized by an open time of greater than about 2 minutes, an opentime of greater than about 4 minutes, an open time of greater than about6 minutes or an open time of greater than about 12 minutes.

In a another embodiment, the latex coating composition of the presentinvention is freeze-thaw stable where the freeze-thaw additive ispresent in the latex coating composition in an amount greater than about2% by weight of the polymer, where the polymer has a Tg of between about−15° C. and about 12° C. and a mean particle size of less than about 200nm, or a Tg of between about −5° C. and about 5° C. and a mean particlesize of less than about 200 nm, or a Tg of between about −5° C. andabout 0° C. and a mean particle size of less than about 200 nm, or a Tgof between about −15° C. and about 12° C. and a mean particle size ofless than about 190 nm, or a Tg of between about −5° C. and about 5° C.and a mean particle size of less than about 190 nm, or a Tg of betweenabout −5° C. and about 0° C. and a mean particle size of less than about190 nm, or a Tg of between about −15° C. and about 12° C. and a meanparticle size of less than about 175 nm, or a Tg of between about −5° C.and about 5° C. and a mean particle size of less than about 175 nm, or aTg of between about −5° C. and about 0° C. and a mean particle size ofless than about 175 nm, where the latex coating composition ischaracterized by an open time of greater than about 2 minutes, an opentime of greater than about 4 minutes, an open time of greater than about6 minutes or an open time of greater than about 12 minutes.

In a further embodiment, the latex coating composition of the presentinvention is freeze-thaw stable where the freeze-thaw additive ispresent in the latex coating composition in an amount greater than about4% by weight of the polymer, and where the polymer has a Tg of betweenabout −15° C. and about 12° C. and a mean particle size of less thanabout 200 nm, or a Tg of between about −5° C. and about 5° C. and a meanparticle size of less than about 200 nm, or a Tg of between about −5° C.and about 0° C. and a mean particle size of less than about 200 nm, or aTg of between about −15° C. and about 12° C. and a mean particle size ofless than about 190 nm, or a Tg of between about −5° C. and about 5° C.and a mean particle size of less than about 190 nm, or a Tg of betweenabout −5° C. and about 0° C. and a mean particle size of less than about190 nm, or a Tg of between about −15° C. and about 12° C. and a meanparticle size of less than about 175 nm, or a Tg of between about −5° C.and about 5° C. and a mean particle size of less than about 175 nm, or aTg of between about −5° C. and about 0° C. and a mean particle size ofless than about 175 nm, where the latex coating composition ischaracterized by an open time of greater than about 2 minutes, an opentime of greater than about 4 minutes, an open time of greater than about6 minutes or an open time of greater than about 12 minutes.

In a further embodiment, the latex coating composition of the presentinvention is freeze-thaw stable where the freeze-thaw additive ispresent in the latex coating composition in an amount greater than about7.5% by weight of the polymer, where the polymer has a Tg of betweenabout −15° C. and about 12° C. and a mean particle size of less thanabout 200 nm, or a Tg of between about −5° C. and about 5° C. and a meanparticle size of less than about 200 nm, or a Tg of between about −5° C.and about 0° C. and a mean particle size of less than about 200 nm, or aTg of between about −15° C. and about 12° C. and a mean particle size ofless than about 190 nm, or a Tg of between about −5° C. and about 5° C.and a mean particle size of less than about 190 nm, or a Tg of betweenabout −5° C. and about 0° C. and a mean particle size of less than about190 nm, or a Tg of between about −15° C. and about 12° C. and a meanparticle size of less than about 175 nm, or a Tg of between about −5° C.and about 5° C. and a mean particle size of less than about 175 nm, or aTg of between about −5° C. and about 0° C. and a mean particle size ofless than about 175 nm, where the latex coating composition ischaracterized by an open time of greater than about 2 minutes, an opentime of greater than about 4 minutes, an open time of greater than about6 minutes or an open time of greater than about 12 minutes.

In a further embodiment, the latex coating composition of the presentinvention is freeze-thaw stable where the freeze-thaw additive ispresent in the latex coating composition in an amount greater than about20% by weight of the polymer, where the polymer has a Tg of betweenabout −15° C. and about 12° C. and a mean particle size of less thanabout 200 nm, or a Tg of between about −5° C. and about 5° C. and a meanparticle size of less than about 200 nm, or a Tg of between about −5° C.and about 0° C. and a mean particle size of less than about 200 nm, or aTg of between about −15° C. and about 12° C. and a mean particle size ofless than about 190 nm, or a Tg of between about −5° C. and about 5° C.and a mean particle size of less than about 190 nm, or a Tg of betweenabout −5° C. and about 0° C. and a mean particle size of less than about190 nm, or a Tg of between about −15° C. and about 12° C. and a meanparticle size of less than about 175 nm, or a Tg of between about −5° C.and about 5° C. and a mean particle size of less than about 175 nm, or aTg of between about −5° C. and about 0° C. and a mean particle size ofless than about 175 nm, where the latex coating composition ischaracterized by an open time of greater than about 2 minutes, an opentime of greater than about 4 minutes, an open time of greater than about6 minutes or an open time of greater than about 12 minutes.

In a further embodiment, the latex coating composition of the presentinvention is freeze-thaw stable where the freeze-thaw additive ispresent in the latex coating composition in an amount between about 1.3%and 7.5% by weight of the polymer, where the polymer has a Tg of betweenabout −15° C. and about 12° C. and a mean particle size of less thanabout 200 nm, or a Tg of between about −5° C. and about 5° C. and a meanparticle size of less than about 200 nm, or a Tg of between about −5° C.and about 0° C. and a mean particle size of less than about 200 nm, or aTg of between about −15° C. and about 12° C. and a mean particle size ofless than about 190 nm, or a Tg of between about −5° C. and about 5° C.and a mean particle size of less than about 190 nm, or a Tg of betweenabout −5° C. and about 0° C. and a mean particle size of less than about190 nm, or a Tg of between about −15° C. and about 12° C. and a meanparticle size of less than about 175 nm, or a Tg of between about −5° C.and about 5° C. and a mean particle size of less than about 175 nm, or aTg of between about −5° C. and about 0° C. and a mean particle size ofless than about 175 nm, where the latex coating composition ischaracterized by an open time of greater than about 2 minutes, an opentime of greater than about 4 minutes, an open time of greater than about6 minutes or an open time of greater than about 12 minutes.

These and other features and advantages of the present invention willbecome more readily apparent to those skilled in the art uponconsideration of the following detailed description, which describe boththe preferred and alternative embodiments of the present invention.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a chart illustrating the Glass Transition temperature (Tg) oflatex binders (prepared from the '514 application description) usingdifferent emulsifying surfactants during emulsion polymerization.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention relates to the use of a particular family ofalkoxylated compounds, e.g., alkoxylated tristyrylphenols andalkoxylated tributylphenols, provided with an ethylene oxide chain forimproving freeze-thaw stability of latex binders and paints. This familyof alkoxylated compounds can improve other properties as well, forexample, open time, stain resistance, film gloss, dispersibility, hidingand scrub resistance, low temperature film formation, foam resistance,block resistance, adhesion and water sensitivity, among others.

As used herein, the term “alkyl” means a saturated hydrocarbon radical,which may be straight, branched or cyclic, such as, for example, methyl,ethyl, n-propyl, iso-propyl, n-butyl, sec-butyl, t-butyl, pentyl,n-hexyl, cyclohexyl.

As used herein, the term “cycloalkyl” means a saturated hydrocarbonradical that includes one or more cyclic alkyl rings, such as, forexample, cyclopentyl, cyclooctyl, and adamantanyl.

As used herein, the term “hydroxyalkyl” means an alkyl radical, moretypically an alkyl radical, that is substituted with a hydroxyl groups,such as for example, hydroxymethyl, hydroxyethyl, hydroxypropyl, andhydroxydecyl.

As used herein, the term “alkylene” means a bivalent acyclic saturatedhydrocarbon radical, including but not limited to methylene,polymethylene, and alkyl substituted polymethylene radicals, such as,for example, dimethylene, tetramethylene, and 2-methyltrimethylene.

As used herein, the term “alkenyl” means an unsaturated straight chain,branched chain, or cyclic hydrocarbon radical that contains one or morecarbon-carbon double bonds, such as, for example, ethenyl, 1-propenyl,2-propenyl.

As used herein, the term “aryl” means a monovalent unsaturatedhydrocarbon radical containing one or more six-membered carbon rings inwhich the unsaturation may be represented by three conjugated doublebonds, which may be substituted one or more of carbons of the ring withhydroxy, alkyl, alkenyl, halo, haloalkyl, or amino, such as, forexample, phenoxy, phenyl, methylphenyl, dimethylphenyl, trimethylphenyl,chlorophenyl, trichloromethylphenyl, aminophenyl.

As used herein, the term “aralkyl” means an alkyl group substituted withone or more aryl groups, such as, for example, phenylmethyl,phenylethyl, triphenylmethyl.

As used herein, the terminology “(C_(n)-C_(m))” in reference to anorganic group, wherein n and m are each integers, indicates that thegroup may contain from n carbon atoms to m carbon atoms per group.

As used herein, the terminology “ethylenic unsaturation” means aterminal (that is, e.g., α, β) carbon-carbon double bond.

The present invention includes latex polymers and latex dispersionshaving low-VOC content and excellent freeze-thaw stability and open timeproperties compared to conventional aqueous coating compositions, aswell as methods of use. Such latex polymers can include at least onelatex polymer copolymerized or blended with a particular family ofalkoxylated compounds. Typically the latex has a Tg of less than 20° C.,more typically less than 15° C., still more typically less than 5° C.More typically, the latex has a Tg in the range of from about −15° C. toabout 12° C., more typically from about −5° C. to about 5° C., moretypically in the range from −5° C. to about 0° C. In one embodiment, thelatex polymer of the present invention has a weight average molecularweight of from about 1,000 to 5,000,000, typically 5,000 to 2,000,000.In another embodiment, the latex polymer of the present invention has aweight average molecular weight of from about 10,000 to 250,000.

The present invention provides aqueous compositions, for example,aqueous coating compositions, having low-VOC content and excellentfreeze-thaw stability and open time properties comparable toconventional aqueous coating compositions. The aqueous compositions ofthe invention are aqueous polymer dispersions which include at least onelatex polymer copolymerized or blended with a particular family ofalkoxylated compounds, e.g., alkoxylated tristyrylphenol. Generally, thelatex polymer is present in such aqueous compositions or paints fromabout 15% to about 40% by weight of the composition for semigloss andfrom about 5% to up to about 75%, typically about 5% to about 50% byweight of the composition for flat paint. Paints or other aqueouscoatings of the present invention typically further include at least onepigment.

The members of the particular family of alkoxylated compounds, e.g.,alkoxylated tristyrylphenols and/or tributylphenols, can be employed ina number of ways for improving freeze-thaw stability of latex bindersand paints. The present invention may employ polymerizable reactivealkoxylated monomers to form a latex comonomer, surface activealkoxylated compounds as a surfactant (emulsifier) to be present duringlatex polymer formation, and/or surface active alkoxylated compounds asan additive to an aqueous dispersion of latex polymer or copolymer.

Reactive polymerizable tristyrylphenol ethoxylates

In one embodiment, polymerizable reactive alkoxylated (second) monomerof the following formula IA can be copolymerized (with a first monomer)into the backbone of the latex polymer.

wherein B is a 5 or 6 membered cycloalkyl ring, e.g., a cyclohexyl ring,or a single ring aromatic hydrocarbon having a 6 membered ring, e.g., abenzene ring;

R1, R2 and R3 are independently selected from:

—H, butyl, tert-butyl, isobutyl,

with the proviso that one or none of R₁, R₂ and R₃ is —H.

wherein, X is C₂H₄, C₃H₆, or C₄H₈, or X is a divalent hydrocarbonradical selected from linear or branched alkylene radicals having from 2to 8 carbon atoms; n is an integer of from 1 to 100, for example fromabout 4 to 80 or 8 to 25; wherein R is an ethylenically unsaturatedgroup. In one embodiment, n is an integer of from 4 to 80. In oneembodiment, n is an integer of from 4 to 60. In one embodiment, n is aninteger of from 10 to 50. In one embodiment, n is an integer of from 10to 25.

Typically, R includes acrylate, or C₁-C₆ alkyl acrylate, e.g.,methacrylate, allyl, vinyl, maleate, itaconate or fumarate, typically Ris acrylate or methacrylate.

Suitable polymerizable functional groups R include, for example, acrylo,methacrylo, acrylamido, methacrylamido, diallylamino, allyl ether, vinylether, α-alkenyl, maleimido, styrenyl, and α-alkyl styrenyl groups.

For example, suitable polymerizable functional groups R have thechemical structure: R^(a)CH═C(R^(b))COO—, wherein if R^(a) is H, thenR^(b) is H, C₁-C₄ alkyl, or —CH₂COOX; if R^(a) is —C(O)OX, then R^(b) isH or —CH₂C(O)OX^(a); or if R^(a) is CH₃, then R^(b) is H and X^(a) is Hor C₁-C₄ alkyl.

For example, other suitable polymerizable functional groups R have thechemical structure: —HC═CYZ or —OCH═CYZ, wherein Y is H, CH₃, or Cl; Zis CN, Cl, —COOR^(c), —C₆H₄R^(c), —COOR^(d), or —HC═CH₂; R^(d) is C₁-C₈alkyl or C₂-C₈ hydroxy alkyl; R^(c) is H, Cl, Br, or C₁-C₄ alkyl.

Typically the monomer has the formula IB:

wherein, R, R₁, R₂, R₃, X and n are as defined for the structure offormula IA. If desired, the aromatic ring shown in structural formula IBmay be saturated. For example, such a saturated monomer may be made bysaturating a form of the monomer wherein H is in the R position and thenreplacing the H in the R position with one of the other above-listed Rgroups.

In one embodiment, at least one monomer can be copolymerized with asecond monomer having structure IB-1:

wherein R is

R₁, R₂ and R₃ are each independently H, branched (C₃-C₈ alkyl), branched(C₄-C₈)alkene or R₅—R₆—;

R₅ is aryl or (C₆-C₈)cycloalkyl,

R₆ is (C₁-C₆)alkylene,

R₇ is a divalent linking group, O, (C₁-C₆)alkylene,

or absent,

R₈ is H or methyl,

R₉ is O or NR₁₀,

R₁₀ is H or (C₁-C₄)alkyl; n is an integer of from 2 to 4, and m is aninteger of from 1 to 100.

In one embodiment, R₁, R₂ and R₃ are independently selected from:

—H, butyl, tert-butyl, isobutyl,

In one embodiment, R can be acrylate, C₁-C₆ alkyl acrylate, allyl,vinyl, maleate, itaconate or fumarate. In one embodiment, R is at leastone of acrylo, methacrylo, acrylamido, methacrylamido, diallylamino,allyl ether, vinyl ether, α-alkenyl, maleimido, styrenyl, and/or α-alkylstyrenyl groups.

In another embodiment, the second monomer is an ethoxylatedtributylphenol. In another embodiment, the monomer is an ethoxylatedtristyrylphenol. The polymerizable reactive ethoxylated tristyrylphenolshave the structural formula IC and the polymerizable reactiveethoxylated tributylphenols have the structural formula IC-1,respectively, as follows:

wherein, n is an integer of from 1-100, for example, 4 to 60 or 8 to 25;

R₄ is a member of the group H, C₁-C₈ hydroxy alkyl, C₁-C₆ alkyl, forexample, CH₃ or C₂H₅.

Thus, the reactive polymerizable ethoxylated tristyrylphenol monomer hasa tristyrylphenol portion, an alkylene oxide portion and a reactivesubstituted or unsubstituted acrylic end group for polymerization.Likewise, the reactive polymerizable ethoxylated tributylphenol monomerhas a tributylphenol portion, an alkylene oxide portion and a reactivesubstituted or unsubstituted acrylic end group for polymerization. Ifdesired, the ethylene oxide group shown in structural formula IC or IC-1may be replaced with the above discussed —(OX)— group to form analkoxylated tristyrylphenol or tributylphenol, respectively, and the—C(O)—CHR₄CH₂ end group may be replaced by allyl, vinyl, maleate,itaconate or fumarate.

Tristyrylphenol ethoxylates, for other uses, are disclosed by U.S. Pat.No. 6,146,570, published PCT patent application number WO 98/012921 andWO 98/045212, incorporated herein by reference.

If desired the aromatic rings of the styryl groups in Formula IC may besaturated.

When reactive polymerizable alkoxylated monomer of IA, IB, IC and/orIC-1 is copolymerized into the backbone of the latex polymer, the latexpolymer is made from a mixture wherein the reactive tristyrylphenol ortributylphenol monomer is 1 to 20 parts per 100 parts by weight ofmonomers used to form the copolymer, more typically 2 to 15, 2 to 8, or2 to 6 parts per 100 parts by weight of monomers used to form thecopolymer. In one embodiment, both the reactive polymerizablealkoxylated monomer of formula IC and IC-1 are utilized andcopolymerized into the backbone of a latex polymer.

Other Monomers

In addition to the polymerizable tristyrylphenol monomer and/orpolymerizable tributylphenol monomer, there are other monomers fromwhich the at least one latex polymer used in the aqueous coatingcomposition, e.g., paint, is typically derived. For purposes of thisdescription, these other monomers from which latex polymers may bederived are termed latex monomers. Typically, these other latex monomerscomprise at least one acrylic monomer selected from the group consistingof acrylic acid, acrylic acid esters, methacrylic acid, and methacrylicacid esters. In addition, the other monomers for making the latexpolymer can optionally be selected from one or more monomers selectedfrom the group consisting of styrene, a-methyl styrene, vinyl chloride,acrylonitrile, methacrylonitrile, ureido methacrylate, vinyl acetate,vinyl esters of branched tertiary monocarboxylic acids (e.g. vinylesters commercially available under the mark VEOVA from Shell ChemicalCompany or sold as EXXAR Neo Vinyl Esters by ExxonMobil ChemicalCompany), itaconic acid, crotonic acid, maleic acid, fumaric acid, andethylene. It is also possible to include C₄-C₈ conjugated dienes such as1,3-butadiene, isoprene and chloroprene. Typically, the monomers includeone or more monomers selected from the group consisting of n-butylacrylate, methyl methacrylate, styrene and 2-ethylhexyl acrylate. Thelatex polymer is typically selected from the group consisting of pureacrylics (comprising acrylic acid, methacrylic acid, an acrylate ester,and/or a methacrylate ester as the main monomers); styrene acrylics(comprising styrene and acrylic acid, methacrylic acid, an acrylateester, and/or a methacrylate ester as the main monomers); vinyl acrylics(comprising vinyl acetate and acrylic acid, methacrylic acid, anacrylate ester, and/or a methacrylate ester as the main monomers); andacrylated ethylene vinyl acetate copolymers (comprising ethylene, vinylacetate and acrylic acid, methacrylic acid, an acrylate ester, and/or amethacrylate ester as the main monomers). The monomers can also includeother main monomers such as acrylamide and acrylonitrile, and one ormore functional monomers such as itaconic acid and ureido methacrylate,as would be readily understood by those skilled in the art. In aparticularly preferred embodiment, the latex polymer is a pure acrylicsuch as a butyl acrylate/methyl methacrylate copolymer derived frommonomers including butyl acrylate and methyl methacrylate.

In one embodiment, the reactive polymerizable alkoxylated monomer offormula IA, IB, IC and/or IC-1 are utilized and copolymerized with oneof the monomers listed under “other monomers” into the backbone of alatex polymer under reaction conditions. In another embodiment, thereactive polymerizable alkoxylated monomer of formula IA, IB, IC and/orIC-1 are utilized and copolymerized with two or more of the monomerslisted under “other monomers” into the backbone of a latex polymer underreaction conditions. In another embodiment, one or more reactivepolymerizable alkoxylated monomers of formula IA, IB, IC and/or IC-1 areutilized and copolymerized with one or more of the monomers listed under“other monomers” into the backbone of a latex polymer under reactionconditions.

The latex polymer dispersion typically includes from about 30 to about75% solids and a mean latex particle size of from about 70 to about 650nm. In another embodiment, the polymer of the present invention has amean particle size of less than about 400 nm, typically a mean particlesize of less than about 200 nm, more typically a mean particle size ofless than about 190 nm, and most typically a mean particle size of lessthan about 175 nm. In another embodiment, the polymer has a meanparticle size of from about 75 nm to about 400 nm.

The latex polymer is typically present in the aqueous coatingcomposition in an amount from about 5 to about 60 percent by weight, andmore typically from about 8 to about 40 percent by weight (i.e. theweight percentage of the dry latex polymer based on the total weight ofthe coating composition).

The resulting aqueous coating composition containing the polymer of thepresent invention is freeze-thaw stable without having to addanti-freeze agents, or adding small amounts of anti-freeze agents, asdescribed above. Therefore, aqueous coating compositions can be producedin accordance with the invention that possess lower VOC levels thanconventional aqueous coating compositions and thus that are moreenvironmentally desirable.

In another embodiment, the resulting latex polymer may be incorporatedinto an aqueous coating composition along with an emulsion surfactant ofthe present invention as described below and/or a freeze-thaw additiveof the present invention as described below. The addition of thefreeze-thaw additive has little or no effect on the VOC levels of theaqueous coating composition, and, thus, aqueous coating compositions canbe produced in that possess lower VOC levels than conventional aqueouscoating compositions. In such an embodiment, the latex coatingcomposition contains a freeze-thaw additive as described herein in anamount greater than about 1.3% by weight of the polymer. In anotherembodiment, the latex coating composition contains a freeze-thawadditive as described herein in an amount greater than about 1.6% byweight of the polymer. In another embodiment, the latex coatingcomposition contains a freeze-thaw additive as described herein in anamount greater than about 2% by weight of the polymer. In anotherembodiment, the latex coating composition contains a freeze-thawadditive as described herein in an amount greater than about 4% byweight of the polymer. In another embodiment, the latex coatingcomposition contains a freeze-thaw additive as described herein in anamount greater than about 7.5% by weight of the polymer. In anotherembodiment, the latex coating composition contains a freeze-thawadditive as described herein in an amount greater than about 8% byweight of the polymer. In another embodiment, the latex coatingcomposition contains a freeze-thaw additive in an amount between about1.6% and 7.5% by weight of the polymer. In another embodiment, the latexcoating composition contains a freeze-thaw additive in an amount betweenabout 1.6% and 45% by weight of the polymer, typically between about1.6% and 35% by weight of the polymer.

In a further embodiment, the polymer of the present invention isfreeze-thaw stable, and can have a Tg of between about −15° C. and about12° C. and a mean particle size of less than about 200 nm, or a Tg ofbetween about −5° C. and about 5° C. and a mean particle size of lessthan about 200 nm, or a Tg of between about −5° C. and about 0° C. and amean particle size of less than about 200 nm, or a Tg of between about−15° C. and about 12° C. and a mean particle size of less than about 190nm, or a Tg of between about −5° C. and about 5° C. and a mean particlesize of less than about 190 nm, or a Tg of between about −5° C. andabout 0° C. and a mean particle size of less than about 190 nm, or a Tgof between about −15° C. and about 12° C. and a mean particle size ofless than about 175 nm, or a Tg of between about −5° C. and about 5° C.and a mean particle size of less than about 175 nm, or a Tg of betweenabout −5° C. and about 0° C. and a mean particle size of less than about175 nm.

The latex polymer including the reactive polymerizable alkoxylatedmonomer of formula IA, IB or IC can be used in combination with otherionic or non-ionic type of surfactants that are either polymerizable ornon-polymerizable, in the aqueous coating composition. In particular,the polymer latex binder can be prepared using emulsion polymerizationby feeding the monomers used to form the latex binder to a reactor inthe presence of at least one initiator and the at least one reactivepolymerizable alkoxylated monomer of formula IA, IB, IC or IC-1 andpolymerizing the monomers to produce the latex binder. The monomers fedto a reactor to prepare the polymer latex binder typically include atleast one acrylic monomer selected from the group consisting of acrylicacid, acrylic acid esters, methacrylic acid, and methacrylic acidesters. In addition, the monomers can include styrene, vinyl acetate, orethylene. The monomers can also include one or more monomers selectedfrom the group consisting of styrene, [alpha]-methyl styrene, vinylchloride, acrylonitrile, methacrylonitrile, ureido methacrylate, vinylacetate, vinyl esters of branched tertiary monocarboxylic acids,itaconic acid, crotonic acid, maleic acid, fumaric acid, and ethylene.It is also possible to include C4-C8 conjugated dienes such as1,3-butadiene, isoprene or chloroprene. Typically, the monomers includeone or more monomers selected from the group consisting of n-butylacrylate, methyl methacrylate, styrene and 2-ethylhexyl acrylate. Theinitiator can be any initiator known in the art for use in emulsionpolymerization such as ammonium or potassium persulfate, or a redoxsystem that typically includes an oxidant and a reducing agent. Commonlyused redox initiation systems are described e.g., by A. S. Sarac inProgress in Polymer Science 24(1999), 1149-1204.

The polymer latex binder can be produced by first preparing an initiatorsolution comprising the initiator and water. A monomer pre-emulsion isalso prepared comprising at least a portion of the monomers to be usedto form the latex polymer, one or more surfactants (emulsifiers), water,and additional additives such as NaOH. The one or more surfactants inthe monomer pre-emulsion include any of the reactive polymerizablealkoxylated monomers of the present invention. The initiator solutionand monomer pre-emulsion are then continuously added to the reactor overa predetermined period of time (e.g. 1.5-5 hours) to causepolymerization of the monomers and to thereby produce the latex polymer.Typically, at least a portion of the initiator solution is added to thereactor prior to adding the monomer pre-emulsion. Prior to the additionof the initiator solution and the monomer pre-emulsion, a seed latexsuch as a polystyrene seed latex can be added to the reactor. Inaddition, water, one or more surfactants, and any monomers not providedin the monomer pre-emulsion can be added to the reactor prior to addingthe initiator and adding the monomer pre-emulsion. The reactor isoperated at an elevated temperature at least until all the monomers arefed to produce the polymer latex binder. Once the polymer latex binderis prepared, it is typically chemically stripped thereby decreasing itsresidual monomer content. Typically, it is chemically stripped bycontinuously adding an oxidant such as a peroxide (e.g.t-butylhydroperoxide) and a reducing agent (e.g. sodium acetonebisulfite), or another redox pair such as those described by A. S. Saracin Progress in Polymer Science 24(1999), 1149-1204, to the latex binderat an elevated temperature and for a predetermined period of time (e.g.0.5 hours). The pH of the latex binder can then be adjusted and abiocide or other additives added after the chemical stripping step.

The aqueous coating composition is a stable fluid that can be applied toa wide variety of materials such as, for example, paper, wood, concrete,metal, glass, ceramics, plastics, plaster, and roofing substrates suchas asphaltic coatings, roofing felts, foamed polyurethane insulation; orto previously painted, primed, undercoated, worn, or weatheredsubstrates. The aqueous coating composition of the invention can beapplied to the materials by a variety of techniques well known in theart such as, for example, brush, rollers, mops, air-assisted or airlessspray, electrostatic spray, and the like.

Latex Polymer Compositions Comprising Surface Active (Emulsifier)Compound

In another embodiment a surface active compound of structural formulaIIA can be used as an emulsifier during the emulsion polymerizationreaction used to make latex polymer.

wherein B is a 5 or 6 membered cycloalkyl ring, e.g., a cyclohexyl ring,or a single ring aromatic hydrocarbon having a 6 membered ring, e.g., abenzene ring;

R₁, R₂ and R₃ are independently selected from:

—H, tertbutyl, butyl,

with the proviso that one or none of R₁, R₂ and R₃ is —H.

wherein, X is at least one member of the group consisting of C₂H₄, C₃H₆,and C₄H₈, or wherein X is a divalent hydrocarbon radical selected fromlinear or branched alkylene radicals having from 2 to 8 carbon atoms; nis 1-100, for example, 3 to 80, 4 to 50, 4 to 40 or 8 to 25;

wherein R is —OH, —OCH₃, —OC₂H₅, —OC₃H₇, —OC₄H₉, —OC₅H₁₁, —OC₆H₁₃, —Cl,—Br, —CN, Phosphonate (—PO₃ ⁻M⁺), Phosphate (PO₄ ⁻M⁺), Sulfate (SO₄⁻M⁺), Sulfonate (SO₃ ⁻M⁺), carboxylate (COO⁻M⁺), a nonionic group, or aquaternary ammonium ion, wherein M+ is a cation including but notlimited to H⁺, Na⁺, NH₄ ⁺, K⁺ or Li⁺,

In one embodiment, R₅ is selected from a quaternary ammonium ion:

In one embodiment, n is an integer of from 4 to 80. In one embodiment, nis an integer of from 4 to 60. In one embodiment, n is an integer offrom 10 to 50. In one embodiment, n is an integer of from 10 to 25.

Typically the alkoxylated surface active compound has the formula IIB:

wherein, R, R₁, R₂, R₃, X and n are as defined for the structure offormula IIA. If desired, the aromatic ring shown in structural formulaIIB may be saturated.

More typically a surface active alkoxylated tristyrylphenol, e.g.,ethoxylated tristyrylphenol, or a surface active alkoxylatedtributylphenol, e.g., ethoxylated tributylphenol can be used as anemulsifier during the emulsion polymerization reaction used to makelatex polymer. The surface active ethoxylated tristyrylphenols have thestructural formula IIC and the surface active ethoxylatedtributylphenols have the structural formula IIC-1, respectively, asfollows:

wherein, n is an integer of from 1 to 100 for example, 4 to 60 or 8 to25, wherein R₅ is —OH, —OCH₃, —OC₂H₅, —OC₃H₇, —OC₄H₉, —OC₅H₁₁, —OC₆H₁₃,—Cl, —Br, —CN, Phosphonate (—PO₃ ⁻M⁺), Phosphate (PO₄ ⁻M⁺), Sulfate (SO₄⁻M⁺), Sulfonate (SO₃ ⁻M⁺), carboxylate (COO⁻M⁺), a nonionic group, or aquaternary ammonium ion, wherein M+ is a cation including but notlimited to H⁺, Na⁺, NH₄ ⁺, K⁺ or Li⁺.

In one embodiment, R₅ is selected from a quaternary ammonium ion:

In one embodiment, n is an integer of from 4 to 80. In one embodiment, nis an integer of from 4 to 60. In one embodiment, n is an integer offrom 10 to 50. In one embodiment, n is an integer of from 10 to 25.

When surface active ethoxylated tristyrylphenol or ethoxylatedtributylphenol is employed as an emulsifier in emulsion polymerizationto form the latex polymer, the latex polymer is made from a mixturewherein the surface active emulsifier utilized is. In one embodiment,the emulsifier is added in an amount greater than 1.3% by weight of thepolymer or monomers used to form the latex polymer, in an amount greaterthan 1.6% by weight of the polymer or monomers used to form the latexpolymer, typically in an amount greater than about 2% by weight of thepolymer or monomers used to form the latex polymer, more typically in anamount greater than about 4% by weight of the polymer or monomers usedto form the latex polymer, and most typically in an amount greater thanabout 7.5% by weight of the polymer or monomers used to form the latexpolymer. In another embodiment, the latex coating composition containsan emulsifier in an amount greater than about 8% by weight of thepolymer or monomers used to form the latex polymer, or greater thanabout 10% by weight of the polymer or monomers. In another embodiment,the emulsifier is added is between about 1.6% and 7.5% by weight of thepolymer or monomers used to form the latex polymer. In anotherembodiment, emulsifier added is between about 1.6% and 45% by weight ofthe polymer or monomers used to form the latex polymer, typicallybetween about 1.6% and 35% by weight of the polymer or monomers used toform the latex polymer

If desired the ethylene oxide repeating units of the ethylene oxidechain of formula IIC or IIC-1 may be replace by the above-described—(OX)— group to form alkoxylated tristyrylphenol or alkoxylatedtributylphenol.

The typical monomers from which the at least one latex polymer(sometimes referred to herein as first monomer or third monomer) isformed are described above in the section entitled “Other Monomers”.

As described above, the polymer latex binder can be produced by firstpreparing an initiator solution comprising the initiator and water. Amonomer pre-emulsion is also prepared comprising at least a portion ofthe monomers to be used to form the latex polymer, one or moresurfactants (emulsifiers), water, and additional additives such as NaOH.The one or more surfactants in the monomer pre-emulsion include thesurface active alkoxylated compound of the invention. Thus, thealkoxylated compound is employed as an emulsifier to form a blend ratherthan as a reactant which copolymerizes with the other monomers whichform the polymer latex binder. The initiator solution and monomerpre-emulsion are then continuously added to the reactor over apredetermined period of time (e.g. 1.5-5 hours) to cause polymerizationof the monomers and to thereby produce the latex polymer. Typically, atleast a portion of the initiator solution is added to the reactor priorto adding the monomer pre-emulsion. Prior to the addition of theinitiator solution and the monomer pre-emulsion, a seed latex such as apolystyrene seed latex can be added to the reactor. In addition, water,one or more surfactants, and any monomers not provided in the monomerpre-emulsion can be added to the reactor prior to adding the initiatorand adding the monomer pre-emulsion. The reactor is operated at anelevated temperature at least until all the monomers are fed to producethe polymer latex binder. Once the polymer latex binder is prepared, itis typically chemically stripped thereby decreasing its residual monomercontent. Typically, it is chemically stripped by continuously adding anoxidant such as a peroxide (e.g. t-butylhydroperoxide) and a reducingagent (e.g. sodium acetone bisulfite), or another redox pair such asthose described by A. S. Sarac in Progress in Polymer Science 24(1999),1149-1204, to the latex binder at an elevated temperature and for apredetermined period of time (e.g. 0.5 hours). The pH of the latexbinder can then be adjusted and a biocide or other additives added afterthe chemical stripping step.

The incorporation of the surface active alkoxylated compound surfactant(emulsifier) in the emulsion polymerization reaction mixture enables thecoating composition to have a lower VOC content while maintaining thefreeze-thaw stability of the aqueous coating composition at desirablelevels.

Additive to an Aqueous Latex Dispersion

In another embodiment the above-described surface active alkoxylatedcompound of structural formula IIA, IIB, IIC or IIC-1 (sometimesreferred to as the freeze-thaw additive) can be used as an additive toan already formed aqueous dispersion of latex polymer. It is understood,that the freeze-thaw additive can be added any point in the productionof the aqueous coating composition, including but not limited to duringthe emulsification step, during formulation, etc. It is also understoodthat the freeze-thaw additive can be post-added to the aqueous coatingcomposition or a concentrate thereof.

This results in an aqueous composition comprising the surface activealkoxylated compound and the latex polymer. When the surface activealkoxylated compound is employed as an additive to an already formedaqueous latex dispersion, the resulting composition has alkoxylatedcompound additive in an amount of about 1 to 10, Typically 2 to 8 or 2to 6, parts per 100 parts by weight of monomers used to form the latexpolymer.

The typical monomers from which the latex polymer is formed aredescribed above in the section entitled “Other Monomers” and can becopolymerized with the reactive monomers of the present invention asdescribed above.

The present invention further includes a method of preparing a latexbinder composition, comprising adding the at least one surface activealkoxylated compound surfactant (emulsifier) of structural formula IIA,IIB, IIC and/or IIC-1 as described above to an aqueous dispersion of alatex polymer to produce the latex binder. The at least one pigment andother additives can then be mixed with the resulting latex binder toproduce the aqueous coating composition in any appropriate order. Theaddition of the surface active alkoxylated compound of structuralformula IIA, IIB, IIC or IIC-1 to the latex polymer forms a mixturehaving a lower VOC content while maintaining the freeze-thaw stabilityof the mixture at desirable levels.

In another embodiment the above-described surface active compound ofstructural formula IIA, IIB, IIC or IIC-1 (sometimes referred to as thefreeze-thaw additive) can be used as an additive to an duringformulation of paint or aqueous coating composition. Formulation is thestage at which additives are added to a base aqueous latex polymerdispersion to make it into final product such as a paint or coating.When the surface active alkoxylated compound is employed as an additiveto an already formed paint or aqueous coating composition, e.g., aqueouslatex coating dispersion, the resulting composition has alkoxylatedcompound additive typically in an amount greater than about 1.3% byweight of the polymer or monomers used to form the latex polymer, moretypically in an amount greater than about 1.6% by weight of the polymeror monomers used to form the latex polymer, yet more typically in anamount greater than about 2% by weight of the polymer or monomers usedto form the latex polymer, even more typically in an amount greater thanabout 4% by weight of the polymer or monomers used to form the latexpolymer, and most typically in an amount greater than about 7.5% byweight of the polymer or monomers used to form the latex polymer. Inanother embodiment, the latex coating composition contains surfaceactive alkoxylated compound in an amount between about 1.6% and 7.5% byweight of the polymer or monomers used to form the latex polymer. Inanother embodiment, the latex coating composition contains surfaceactive alkoxylated compound in an amount between about 1.6% and 45% byweight of the polymer or monomers used to form the latex polymer,typically between about 1.6% and 35%. Pigment is a typical additive, forexample, added during formulation of paint from raw aqueous latexpolymer dispersion.

The aqueous coating compositions of the present invention arefreeze-thaw stable where the freeze-thaw additive is present in theaqueous coating composition in the amounts by weight of the polymer asdescribed above, where the polymer can have a Tg of between about −15°C. and about 12° C. and a mean particle size of less than about 200 nm,or a Tg of between about −5° C. and about 5° C. and a mean particle sizeof less than about 200 nm, or a Tg of between about −5° C. and about 0°C. and a mean particle size of less than about 200 nm, or a Tg ofbetween about −15° C. and about 12° C. and a mean particle size of lessthan about 190 nm, or a Tg of between about −5° C. and about 5° C. and amean particle size of less than about 190 nm, or a Tg of between about−5° C. and about 0° C. and a mean particle size of less than about 190nm, or a Tg of between about −15° C. and about 12° C. and a meanparticle size of less than about 175 nm, or a Tg of between about −5° C.and about 5° C. and a mean particle size of less than about 175 nm, or aTg of between about −5° C. and about 0° C. and a mean particle size ofless than about 175 nm. As described above, the mean particle size istypically between about 75 nm to about 400 nm. The aqueous coatingcomposition can be characterized by an open time of greater than about 2minutes, an open time of greater than about 4 minutes, an open time ofgreater than about 6 minutes or an open time of greater than about 12minutes.

The present invention further includes a method of preparing a paint oraqueous coating composition, comprising adding the at least one surfaceactive alkoxylated compound of structural formula IIA, IIB, IIC and/orIIC-1 as described above during formulation of paint or aqueous coatingcomposition comprising at least one pigment and other additives toproduce the final paint or aqueous coating composition. The addition ofthe surface active alkoxylated compound surfactant (emulsifier) duringformulation of paint or aqueous coating composition forms a coatingcomposition having a lower VOC content while maintaining the freeze-thawstability of the aqueous coating composition at desirable levels.

Other Additives

The aqueous coating compositions of the invention include at least onelatex polymer derived from at least one monomer, for example acrylicmonomers and/or the other above-described latex monomers. The aqueouscoating compositions of the invention include less than 2% by weight andtypically less than 1.0% by weight of anti-freeze agents based on thetotal weight of the aqueous coating composition. More typically, theaqueous coating compositions are substantially free of anti-freezeagents.

The aqueous coating composition typically includes at least one pigment.The term “pigment” as used herein includes non-film-forming solids suchas pigments, extenders, and fillers. The at least one pigment istypically selected from the group consisting of TiO2 (in both anastaseand rutile forms), clay (aluminum silicate), CaCO3 (in both ground andprecipitated forms), aluminum oxide, silicon dioxide, magnesium oxide,talc (magnesium silicate), barytes (barium sulfate), zinc oxide, zincsulfite, sodium oxide, potassium oxide and mixtures thereof. Suitablemixtures include blends of metal oxides such as those sold under themarks MINEX (oxides of silicon, aluminum, sodium and potassiumcommercially available from Unimin Specialty Minerals), CELITES(aluminum oxide and silicon dioxide commercially available from CeliteCompany), ATOMITES (commercially available from English China ClayInternational), and ATTAGELS (commercially available from Engelhard).More typically, the at least one pigment includes TiO2, CaCO3 or clay.Generally, the mean particle sizes of the pigments range from about 0.01to about 50 microns. For example, the TiO2 particles used in the aqueouscoating composition typically have a mean particle size of from about0.15 to about 0.40 microns. The pigment can be added to the aqueouscoating composition as a powder or in slurry form. The pigment istypically present in the aqueous coating composition in an amount fromabout 5 to about 50 percent by weight, more typically from about 10 toabout 40 percent by weight.

The coating composition can optionally contain additives such as one ormore film-forming aids or coalescing agents. Suitable firm-forming aidsor coalescing agents include plasticizers and drying retarders such ashigh boiling point polar solvents. Other conventional coating additivessuch as, for example, dispersants, additional surfactants (i.e. wettingagents), rheology modifiers, defoamers, thickeners, biocides,mildewcides, colorants such as colored pigments and dyes, waxes,perfumes, co-solvents, and the like, can also be used in accordance withthe invention. For example, non-ionic and/or ionic (e.g. anionic orcationic) surfactants can be used to produce the polymer latex. Theseadditives are typically present in the aqueous coating composition in anamount from 0 to about 15% by weight, more typically from about 1 toabout 10% by weight based on the total weight of the coatingcomposition.

As mentioned above, the aqueous coating composition in some embodimentscan include less than 2.0% of anti-freeze agents based on the totalweight of the aqueous coating composition. Exemplary anti-freeze agentsinclude ethylene glycol, diethylene glycol, propylene glycol, glycerol(1,2,3-trihydroxypropane), ethanol, methanol, 1-methoxy-2-propanol,2-amino-2-methyl-1-propanol, and FTS-365 (a freeze-thaw stabilizer fromInovachem Specialty Chemicals). More typically, the aqueous coatingcomposition includes less than 1.0% or is substantially free (e.g.includes less than 0.1%) of anti-freeze agents. Accordingly, the aqueouscoating composition of the invention typically has a VOC level of lessthan about 100 g/L and more typically less than or equal to about 50g/L. Despite the fact that the aqueous coating compositions of theinvention include little or no anti-freeze agents, the compositionspossess freeze-thaw stabilities at levels desirable in the art.

For example, the aqueous coating compositions of the invention can besubjected to freeze-thaw cycles using ASTM method D2243-82 or ASTMD2243-95 without coagulation.

The balance of the aqueous coating composition of the invention iswater. Although much of the water is present in the polymer latexdispersion and in other components of the aqueous coating composition,water is generally also added separately to the aqueous coatingcomposition. Typically, the aqueous coating composition includes fromabout 10% to about 85% by weight and more typically from about 35% toabout 80% by weight water. Stated differently, the total solids contentof the aqueous coating composition is typically from about 15% to about90%, more typically, from about 20% to about 65%.

The coating compositions are typically formulated such that the driedcoatings comprise at least 10% by volume of dry polymer solids, andadditionally 5 to 90% by volume of non-polymeric solids in the form ofpigments. The dried coatings can also include additives such asplasticizers, dispersants, surfactants, rheology modifiers, defoamers,thickeners, biocides, mildewcides, colorants, waxes, and the like, thatdo not evaporate upon drying of the coating composition.

In one preferred embodiment of the invention, the aqueous coatingcomposition is a latex paint composition comprising at least one latexpolymer derived from at least one acrylic monomer selected from thegroup consisting of acrylic acid, acrylic acid esters, methacrylic acid,and methacrylic acid esters and at least one polymerizable alkoxylatedsurfactant; at least one pigment and water. As mentioned above, the atleast one latex polymer can be a pure acrylic, a styrene acrylic, avinyl acrylic or an acrylated ethylene vinyl acetate copolymer.

The present invention further includes a method of preparing an aqueouscoating composition by mixing together at least one latex polymerderived from at least one monomer and copolymerized and/or blended withat least one tristyrylphenol as described above, and at least onepigment. Typically, the latex polymer is in the form of a latex polymerdispersion. The additives discussed above can be added in any suitableorder to the latex polymer, the pigment, or combinations thereof, toprovide these additives in the aqueous coating composition. In the caseof paint formulations, the aqueous coating composition typically has apH of from 7 to 10.

The present invention will now be further described by the followingnon-limiting examples. As described above, the present invention mayemploy (I) surface active alkoxylated compounds as a surfactant(emulsifier) to be present during latex polymer formation, (II)polymerizable reactive alkoxylated monomers to form a latex comonomer,and/or (III) surface active alkoxylated compounds as an additive to anaqueous dispersion of latex polymer or copolymer.

EXAMPLES

The following Example 1 and its subsets describe the present inventionas surface active alkoxylated compounds utilized as a surfactant(emulsifier) to be present during latex polymer formation.

Example 1

Freeze Thaw Stability Study—Example 1 compares a control withcompositions of the present invention, which incorporate various levelsof TSP-EO and 1% MM (methacrylic acid). TSP-EO is a surface activeethoxylated tristyrylphenol according to the above-listed structuralformula IIC in which the R group is H.

Sample 1 of the present invention with 2% TSP-EO, 1% MM (methacrylicacid); Sample 2 of the present invention with 4% TSP-EO, 1% MM; andSample 3 of the present invention with 6% TSP-EO, 1% MM were made. TABLE1 shows the ingredients of Sample 2 which is an embodiment of thepresent invention with 4% TSP-EO, 1% MM.

TABLE 1 SAMPLE 2 INGREDIENTS Ingredient weight Recipe: (grams) % BOTMKettle Charge Deionized Water 200.00 Monomer Emulsion Deionized Water176.25 Alkyl sulfate surfactant 18.75 1.50 Non-ionic surfactant 5.000.50 TSP - EO 20.00 4.00 Methylmethacrylate (MMA) 200.00 40.00butylacrylate (BA) 295.00 59.00 (methyl acrylic acid) MAA 5.00 1.00Initiator Solution Deionized Water 98.00 Ammonium Persulfate 2.00 0.40Total 1020.00 106.40 Total 1020.00 Theoretical % Solids =

“BOTM” is an abbreviation for “Based On Total Monomer.” The monomeremulsion contains typical monomers for making latex. As mentioned above,TSP-EO contains a surface active tristyrylphenol with from about 10 toabout 50 ethylene oxide groups in its alkoylate chain according to theabove-listed structural formula IIC in which the R group is H. RHODACALA-246/L and ABEX are emulsifiers available from Rhodia Inc., Cranbury,N.J.

TABLE 2 shows the ingredients employed in a control tested in thisexample.

TABLE 2 CONTROL INGREDIENTS Recipe: Ingredient weight (g) % BOTM KettleCharge Deionized Water 320.00 Monomer Emulsion Deionized Water 282.00Alkyl sulfate surfactant 30.00 1.50 Non-ionic surfactant 8.00 0.50Methylmethacrylate 320.00 40.00 (MMA) butylacrylate (BA) 472.00 59.00(methyl acrylic acid) 8.00 1.00 MAA Initiator Solution Deionized Water156.80 Ammonium Persulfate 3.20 0.40 Total 1600.00 102.40 TotalTheoretical % Solids =

PROCEDURE: The control and the Sample 1, 2 and 3 ingredients wererespectively each employed in an emulsion polymerization reactionprocedure as follows:

1. Heat kettle charge to about 80° C. while purging with N₂. Maintain N₂blanket throughout run.

2. Prepare Monomer emulsion and Initiator solution based on the abovedescribed recipe.

3. At about 80° C. add Initiator solution and Monomer emulsion to thekettle.

4. Hold at about 80° C. for about 10-20 minutes.

5. Slowly add the remainder of the Monomer emulsion and Initiatorsolution over 3 hours while maintaining the reaction temperature atabout 80±1° C.

6. After addition of the Monomer emulsion and Initiator solution iscompleted, the reaction mixture temperature was heated to about 85° C.and held over 30 minutes.

7. Cool reactor contents to below about 30° C. Adjust the pH of finalreaction to 8-9.

8. Filter the batch through a 100 mesh filter and store in a closedcontainer for characterization.

Sample 1 contained 4% TSP-EO. The procedure was repeated for 2% TSP-EOand 6% TSP-EO samples that were the same as the 4% TSP-EO sample exceptfor the amount of TSP-EO.

TABLE 3 shows the results of the control, the 2% TSP-EO sample (Sample1), the above-described 4% TSP-EO sample (Sample 2), and the 6% TSP-EOsample (Sample 3). The freeze-thaw stability of polymer dispersions andformulated paints was measured based on ASTM standard test MethodD2243-95. The latexes or formulated paints are tested using a half pintof sample. The sample was kept in a freezer at 0° F. (−18° C.) over 17hours and then taken out from the freezer and allowed to thaw for 7hours at room temperature. The freeze-thaw cycles were continued untilthe latex or paint coagulated, or to a maximum of five (5) cycles.

TABLE 3 2% 4% 6% TSP - EO TSP - EO TSP - EO Control (Sample 1) (Sample2) (Sample 3) 1. Coagulum 0.5 17 0.5 0.5 (based on total latex) 2. pH ofaqueous 8.86 8.83 8.9 8.81 latex dispersion after neutralization 3.Latex Solid in 50.78 49.94 51.1 51.6 dispersion, % 4. BrookfieldViscosity of aqueous latex polymer dispersion Spindle/ LV3/LVT LV3/ LV3/LV3/ Instrument Used Model LVT Model LVT Model LVT Model at 60 rpm (cps)100 90 70 70 5. Particle Size Weight Average 180.6 172.8 164.2 156.3Std. Dev. % 11.73 6.73 9.8 9.9 6. Freeze-Thaw Stability Cycle1 (cps)gelled 400 600 1560 Cycle 2 520 680 1500 Cycle 3 500 580 1300

TABLE 3 shows the additive of the present invention prevented gelling atconditions which gelled the control. Coagulum particles are formed as abyproduct of making latex. The Tg of the latex, as measured using theDSC method as generally known in the art, was 3.63° C.

Example 1-1

The above-described procedure was repeated with a variety of anionic ornonionic ethoxylated tristerylphenolic (TSP) compounds having from about6 ethylene oxide groups to about 60 ethylene oxide groups. TABLE 4presents the results of these examples.

TABLE 4 Effects of Additives on Freeze-Thaw Stability of Water-BornePaints² Freeze-Thaw Stability Viscosity (KU)¹ Starting 2 3 4 5 AdditivesViscosity 1 cycle cycles cycles cycles cycles TSP-EO #1 102.4 103.8104.3 104 104 105.4 TSP-EO #2 98.3 101.9 102.2 101.2 100.2 101.3 TSP-EO#3 82.9 86.6 88.8 89.4 90.4 91.5 TSP-EO #4 78 88.3 90.2 91.6 93.3 101.4TSP-EO #5 78.4 82 86.4 86 85.4 87.1 TSP-EO #6 80.8 91.9 95.1 96.2 96.597.6 Ethoxylated 95.5 Failed nonylphenol³ (gelled) Control 121.1 Failed(Low VOC (gelled) Commercial Paint) Notes: ¹Additive loading level: 1.0Wt % of total paint weight. ²Water-borne commercial paint: Weight perGallon: 10.24 pounds per gallon; pH: 8.67; VOC: <50 g/L; Gloss at 60degrees: 52. ³Nonylphenol moiety attached to 9EO

Example 2 illustrates comparative examples of the present invention asagainst the disclosure of International Publication Number WO2007/117512 (hereinafter sometimes referred to as the “'512 Application”or “Stepan”).

Example 2

The seed latex according to the '512 Application (p. 20) was prepared:

Seed Latex Preparation using Sodium Lauryl Sulfate (SLS)

Formulas: Water 50 Sulfate*: (29.5) 2.44 Monomers: Styrene 7.2 MMA 12.24BA 15.84 AA 0.72 Total 100 Initiator Solution Ammonium Persulfate 0.26Water 14

Procedure: 1. Add 150 water and 7.32 g surfactant (SLS) to the kettleand heat to ˜83° C. 2. Add 42.78 g initiator solution. 3. Add 108monomer mixture to kettle and hold at ˜83° C. over 2-3 hours. 4. Measurethe particle size during emulsion polymerization process. 5. Cool toroom temperature and keep the seed latex for future usage. The active wt% of the seed latex was 36 wt %.

Tables 5 and 6 illustrate emulsion polymerization of a styrene-acryliclatex polymer using SLS (control) and using SLS in combination with aTSP having from about 10 to 40 ethylene oxide groups as surfactantemulsifiers, respectively.

TABLE 5 Styrene-Acrylic Latex Polymer - Sodium Lauryl Sulfate (Control)Recipe: Ingredient weight (g) % BOTM Kettle Charge Deionized Water220.00 NaHCO3 solution 25.00 Styrene-Acrylic Seed 30.00 Monomer EmulsionDeionized Water 150.00 Sodium Lauryl Sulfate 11.19 0.65 TSP 0 0.00Styrene 100.00 20.00 MMA 170.00 34.00 BA 220.00 44.00 AA 10.00 2.00Initiator Solution Deionized Water 95.50 Ammonium Persulfate 3.50 0.70NaHCO3 Solution NaHCO3 Solution 125.00 Total 1160.19 Total 1160.19Theoretical % Solids = Scale-up factor = Seed = ME 30.00 IS 20.00

TABLE 6 Styrene-Acrylic Latex Polymer - Sodium Lauryl Sulfate & TSP-EORecipe: Ingredient weight (g) % BOTM Kettle Charge Deionized Water220.00 NaHCO3 solution 25.00 Styrene-Acrylic Seed 30.00 Monomer EmulsionDeionized Water 150.00 Sodium Lauryl Sulfate 11.19 0.65 TSP-EO 6.5 1.3Styrene 100.00 20.00 MMA 170.00 34.00 BA 220.00 44.00 AA 10.00 2.00Initiator Solution Deionized Water 95.50 Ammonium Persulfate 3.50 0.70NaHCO3 Solution NaHCO3 Solution 125.00 Total 1166.69 Total 1166.69Theoretical % Solids = Scale-up factor = Seed = ME 30.00 IS 20.00

Procedure (for Tables 5 and 6):

1) Charge water and 25 g of NaHCO3 solution and 30 g seed latex to akettle and heat the kettle to about 83° C. at a stirring rate of 150 rpmwhile purging with N2. Maintain N2 blanket throughout run. 2) Preparemonomer emulsion and initiator solution based on the recipe. 3) At ˜83°C. add 20.2% Initiator solution (20.0 g) and hold for 8 minutes. 4) Feedremainder of Monomer emulsion over about 180 minutes and maintain thereaction temperature at about 83±1° C. 5) After 10 minutes of monomersadditions, 79 g solution of ammonium persulfate solution with 125.0 gNaHCO₃ solution was fed for 180 minutes. 6) After addition, heat thereaction temperature to 83° C. and hold over 60 minutes at 83±1° C. 7)Cool batch to below 30° C., and adjust pH to 8.5±0.1 with concentrated(28%) ammonium hydroxide solution. 8) Filter the batch through a 100mesh filter and store in a closed container for characterization.

TABLE 7 Resulting Properties of styrene-acrylic latex polymer using SLS(control) and using SLS in combination with a TSP as surfactantemulsifiers Control - Polymer with Polymer with Sodium Lauryl Sulfate(SLS) SLS + TSP-EO PROPERTIES: % Coagulum 0.08 0.21 % Solids 44.27 45.33% Conversion 98.16 100 pH (init) 5.10 5.05 pH (adjust) 8.50 8.50Particle size (nm) 200.7 200 Viscosity (cps) 100 80 LV3, 60 F/T cyclesYes Yes

Table 8—Freeze-Thaw Stability of latex binder using SLS (control) andTDA Sodium Sulfate (control), as compared to using SLS in combinationwith a TSP as surfactant emulsifiers and using TDA Sodium Sulfate incombination with a TSP as surfactant emulsifiers, respectively.

TABLE 8 Freeze-Thaw Stability of Latex Viscosity (cPs, Brookfield) (LV4,60 rpm) Initial 1 Latex Binders Vis. cycle 2 cycles 3 cycles 4 cycles 5cycles Latex Binder with 150 950 900 600 650 550 SLS Latex Binder with150 700 650 550 550 550 SLS/TSP-EO Latex Binder with 150 800 650 700 600510 TDA sodium Sulfate Latex Binder with 150 600 500 550 550 500 TDAsodium Sulfate/TSP-EO

Referring to Tables 7 and 8, the properties of the latex polymerdispersions prepared in Table 5 (Sodium Lauryl Sulfate used as theemulsifying surfactant) and Table 6 (Sodium Lauryl Sulfate and TSP usedas emulsifying surfactants) both exhibit freeze thaw (F/T) stability.Using the DSC method generally known in the art, the measured Tg of thelatex dispersion of Tables 5 and 6 ranged from about 24° C.-27° C.

Referring to FIG. 1, the Tg of various latex polymers prepared under the'512 application are illustrated: (1) emulsion polymerization of thelatex polymer using SLS, which has a measured Tg of about 26.5° C.; (2)emulsion polymerization of the latex polymer using SLS in combinationwith a TSP-EO as surfactant emulsifiers, which has a measured Tg ofabout 25.3° C.; (3) emulsion polymerization of the latex polymer usingTDA Sodium Sulfate, which has a measured Tg of about 24.5° C.; and (4)emulsion polymerization of the latex polymer using TDA Sodium Sulfate incombination with a TSP-EO as surfactant emulsifiers, which has ameasured Tg of about 26.5° C.

The following Example 3 and its subsets describe the present inventionas polymerizable reactive alkoxylated monomers (reactive monomers) usedto form a latex comonomer or polymer.

Example 3

The following examples relate to use of tristyrylphenol (TSP)ethoxylates and tributylphenol (TBP) ethoxylates utilized as reactivemonomers in preparing latex.

Example 3-1 Preparing Latex Polymers

Referring to Table 9, a control latex polymer was prepared from emulsionpolymerization without the use of TSP/TBP ethoxylated monomers.Referring to Table 10, a latex polymer was prepared from emulsionpolymerization using TSP ethoxylated monomers and TBP ethoxylatedmonomers of the present invention. The procedure for preparing the latexpolymer was as follows:

Heat kettle charge to while purging with N₂. Maintain N₂ blanketthroughout run. Prepare monomer emulsion and initiator solution. Addinitiator solution and monomer emulsion. Hold at steady temperature andfeed remainder of monomer emulsion and Initiator solution. Cool toreactor below 30° C. and then filter the batch through cheesecloth.

TABLE 9 Emulsion Polymerization without TSP/TBP ethoxylated monomerRecipe: Ingredient weight (g) % BOTM Kettle Charge Deionized Water320.00 Monomer Emulsion Deionized Water 282.00 Alkyl sulfate surfactant30.00 1.50 Non-ionic surfactant 8.00 0.5 MMA 320.00 40.00 BA 472.0059.00 MAA 8.00 1.00 Initiator Solution Deionized Water 156.80 AmmoniumPersulfate 3.20 0.40 Chaser Solution Total 1600.00 Total 1600.00Theoretical % Solids = Scale-up factor = Seed = ME 56.00 IS 40.00

TABLE 10 Emulsion Polymerization utilizing TSP ethoxylated monomerRecipe: Ingredient weight (g) % BOTM Kettle Charge Deionized Water200.00 Monomer Emulsion Deionized Water 176.25 Alkyl sulfate surfactant18.75 1.50 Non-ionic surfactant 5.00 0.50 TSP-EO 16.60 2.00 MMA 200.0040.00 BA 295.00 59.00 MAA 1.68 1.00 Initiator Solution Deionized Water98.00 Ammonium Persulfate 2.00 0.40 Chaser Solution Total 1013.28 Total1013.28 Theoretical % Solids = Scale-up factor = Seed = ME 35.66 IS25.00

Example 3-2 Paint Formulations

Tables 11, 12 and 13 illustrate paint formulations utilizing acommercially low VOC available paint whose polymer latex is believed tohave a Tg of about 2.4° C. and a D₅₀ of between 130-160, a similarformulation utilizing pure acrylic as the latex polymer, and a similarformulation utilizing the synthesized latexes of the present inventionas the latex polymer, respectively.

TABLE 11 Paint Formulation Control - Commercially available Low VOCpaint (Comm. Paint) Raw materials Pounds Gallons Weight Percent PigmentGrind Water 80 9.62 9.560 Ethylene Glycol 0 0 0 AMP-95 1 0.13 0.10Rhodoline 286N 8 0.91 0.76 Antarox BL-225 4 0.48 0.38 Rhodoline 643 0.50.06 0.05 Attagel 50 5 0.253 0.48 Titanium dioxide Tiona 230 7 22.0 595Water 89.6 10.77 6.64 Sub Total 418.1 29.22 Letdown Comm. latex 480 54.245.9 (undisclosed) Texanol 0 0 0 Rhodoline 643 2.5 0.41 0.29 AquaflowNHS310 28 3.23 2.68 Water 95 11.42 9.1 Acrysol ™ SCT-275 14 1.634 0.67Polyphase 663 4 0.418 0.38 Total 1041.6 100.53 100.0

TABLE 12 Paint Formulation Control - Pure Acrylic Raw materials PoundsGallons Weight Percent Pigment Grind Water 80 9.62 9.560 Ethylene Glycol0 0 0.00 AMP-95 1 0.13 0.10 Rhodoline 286N 8 0.91 0.76 Antarox BL-225 40.48 0.38 Rhodoline 643 0.5 0.06 0.05 Attagel 50 5 0.253 0.48 Titaniumdioxide Tiona 230 7 22.0 595 Water 89.6 10.77 6.64 Sub Total 418.1 29.22Letdown Pure Acrylic - Control 480 54.2 45.9 Texanol 0 0 0.0 Rhodoline643 2.5 0.41 0.29 Aquaflow NHS310 28 3.23 2.68 Water 95 11.42 9.1Acrysol ™ SCT-275 14 1.634 0.67 Polyphase 663 4 0.418 0.38 Total 1041.6100.53 100.0

TABLE 13 Paint Formulation with synthesized latex including TSPethoxylate unit Raw materials Pounds Gallons Weight Percent PigmentGrind Water 80 9.62 9.560 Ethylene Glycol 0 0 0.00 AMP-95 1 0.13 0.10Rhodoline 286N 8 0.91 0.76 Antarox BL-225 4 0.48 0.38 Rhodoline 643 0.50.06 0.05 Attagel 50 5 0.253 0.48 Titanium dioxide Tiona 230 7 22.0 595Water 89.6 10.77 6.64 Sub Total 418.1 29.22 Letdown Latex-2% - TSP/TBP480 54.2 45.9 reactive monomer Texanol 0 0 0.0 Rhodoline 643 2.5 0.410.29 Aquaflow NHS310 28 3.23 2.68 Water 95 11.42 9.1 Acrysol ™ SCT-27514 1.634 0.67 Polyphase 663 4 0.418 0.38 Total 1041.6 100.53 100.0

Table 14 illustrates the resulting paint properties of the abovereferenced paint formulations using low Tg commercial latex, pureacrylic latex, and varying TSP/TBP ethoxylated monomers havingethoxylate groups from about 3 to 80.

TABLE 14 R- R- R- R- R- R- Comm. Pure TSP TSP TSP TSP TSP TSP R-TSPR-TBP R-TBP Latex Acrylic #1 #2 #3 #4 #5 #6 #7 #1 #2 Viscosity: InitialKU 106.8 103 101.5 100.3 97 84.5 80.1 95.6 86.6 98.6 88.4 Initial, ICI1.2 1.4 1.6 1.5 1.6 1.3 1.4 1.3 1.4 1.7 1.4 Viscosity, equilibrium KU113.4 106.3 103.8 103.1 99.4 88.7 82.3 93.6 87.1 101 93.8 ICI 1.3 1.41.6 1.6 1.4 1.2 1.4 1.4 1.3 1.6 1.2 pH 8.3 8.55 8.47 8.6 8.42 8.51 8.558.54 8.44 8.55 8.45 WPG 10.42 10.36 10.39 10.4 10.38 10.28 10.34 10.329.88 10.27 10.35 Gloss 20.1/ 21.2/ 19.2/ 21.7/ 20.3/ 20.8/ 21.3/ 12.3/2.9/ 16.5/ 17.0/ 20/60/85 57.9/ 60.3/ 56.9/ 60.8/ 59.2/ 59/ 59.9/ 52.6/21.5/ 54.5/ 54.8/ 88.4 89.4 86.4 89.6 87.3 87.8 88.4 81.6 40.6 87.6 87.5

The paint formulations utilizing Comm. Latex and Pure Acrylic latexgelled only after one F/T cycle as opposed to formulations using latexesincorporating several TSP/TBP ethoxylated monomers, which exhibited F/Tstability.

Example 3-3

The properties of paint formulations using a control latex (pureacrylic), a commercially-available low Tg latex, and the TSP reactivemonomers of the present invention were tested. It is observed that theresulting paint formulations wherein the above-referenced latexes variedproduced comparable properties aside from F/T stability. Accordingly,the imparting of F/T stability using the reactive TSP and TBP monomerethoxylates into latex polymers of the present invention does notdetract from other desirable properties of the paint formulation (10being the highest to 1 being the lowest).

TABLE 15 paint properties Benchmark - Low VOC commercial Control - Purepaint (Comm. Acrylic Latex) R-TSP-EO #1 R-TSP-EO #2 WPG 9.35 10.03 9.69.37 pH 8.55 8.3 8.54 8.49 Viscosity 77 109 94 77 ICI 1.00 1.60 1.051.05 Gloss - 16.5/54.3/90.7 21.2/60.6/92.9 17.2/56.4/86.4 15.3/55.5/95.3@20/60/85° Reflectance 93.9 94 93.5 93.8 Contrast Ratio 0.972 0.9770.972 0.971 Low Temp. Film Formation, 40° F. Sealed 10 10 10 10 Unsealed10 10 10 10 Surfactant Leaching 24 hours Dry 8 7 7 8  3 Days Dry 8 7 7 8 7 Days Dry 9 7 7 8 Foam Dab Test 9 9 9 9 Leveling - ASTM 10 8 9 8 D4062Block Resistance, ASTM D 4946 RT 7 7 7 7 Dry Adhesion, 7 Days Aluminum0B 2B 1B 2B Alkyd 5B 5B 5B 4B Open Time, minutes  0 10 10 10 10  2 10 1010 10  4 9 8 9 9  6 8 7 8 8  8 8 6 7 6 10 7 5 5 5 12 6 4 4 4 14 5 3 3 3Color Acceptance E Colorant 9 10 8 10 B Colorant 9 10 7 10

TABLE 16 Scrub resistance of the present invention as compared to thecontrol (pure acrylic latex). Scrub Resistance R-TSP-EO #1 ControlR-TSP-EO #2 Control Run 1 838 1393 978 1206 Run 2 818 1370 1086 1337

TABLE 17 Scrub resistance of the present invention as compared to a lowVOC commercially-available paint formulation (Comm. Latex). ScrubResistance R-TSP-EO #1 Comm. Paint R-TSP-EO #2 Comm. Paint Run 1 7362218 1078 1897 Run 2 838 2115 943 1930

TABLE 18 stain removal properties of the present invention as comparedto the control (pure acrylic latex). Stain Removal R-TSP-EO #1 ControlR-TSP-EO #2 Control Purple Crayon 10 10 10 10 Pencil 10 10 10 10 RedLipstick 6 7 6 7 Ball Point Pen 5 5 5 5 Black Washable 7 7 7 7 MarkerBlack Sanford 10 10 10 10 Highlighter Yellow Gulden's 6 6 6 6 MustardCoffee 6 6 5 6 Red Wine 4 5 5 5

TABLE 19 stain removal properties of the present invention as comparedto a low VOC commercially-available paint formulation (using low TgComm. Latex). Comm. Stain Removal R-TSP-EO #1 Comm. Paint R-TSP-EO #2Paint Purple Crayon 10 10 10 10 Pencil 10 10 10 10 Red Lipstick 6 7 7 7Ball Point Pen 4 5 5 6 Black Washable 7 7 7 7 Marker Black Sanford 10 1010 10 Highlighter Yellow Gulden's 5 5 5 5 Mustard Coffee 6 6 6 6 RedWine 4 4 4 4

The following Example 4 and its subsets describe the present inventionas surface active alkoxylated compounds utilized as one or moreadditives to an aqueous dispersion of latex polymer or copolymer.

Example 4

Surface Active Alkoxylated Compounds as Additives.

Non-ionic TSP surfactants having ethylene oxide groups greater thanabout 3 to about 80 was added at 10 lbs/100 gals in Pure acrylic—Whitebase, and the formulation exhibited freeze-thaw stability.

Table 20 shows anionic TSP surfactants of the present invention (10lbs/100 gals) as F/T additives (in Pure acrylic—White base).

TABLE 20 Freeze-Thaw Stability of Low VOC Paints Commercial SemiglossPaint with varying amounts of Stormer Viscosity (Krebs Unit, KU)(anionic) F/T Initial 1 2 3 4 additive Vis. cycle cycles cycles cycles 5cycles TSP-EO 82.9 86.6 88.8 89.4 90.4 91.5 phosphate ester salt Lownonionic TSP- 77.8 85.6 87.4 88.0 89.6 91.2 EO phosphate ester saltTSP-EO TEA salt 81.7 91.0 93.5 94.0 95.5 97.9 TSP-EO 78.0 88.3 90.2 91.693.3 101.4 Ammonium Sulfate Salt TSP-EO 76.6 84.8 85.1 86.2 85.9 86.7Potassium Salt 1 TSP-EO 81.3 90.7 92.6 93.8 93.3 94.7 Potassium Salt 2TSP-EO-PO 81.3 92.6 95.3 97.8 102.2 104.9

Example 4-1

Table 21 shows the effects of the TSP ethoxylate of the presentinvention on the binder particle size. The mean particle size wasmeasured using a Zetasizer Nano ZS device utilizing the Dynamic LightScattering (DLS) method. The DLS method essentially consists ofobserving the scattering of laser light from particles, determining thediffusion speed and deriving the size from this scattering of laserlight, using the Stokes-Einstein relationship.

TABLE 21 Effects of TSP Ethoxylate on Particle sizes of Low Tg BinderLow VOC Comm. Mean Particle Size (nm) Paint Initial 1 TSP (3.0 wt %)Vis. cycle 2 cycles 3 cycles 4 cycles 5 cycles TSP-EO 220.75 + 142.8137.5 149.9 154.3 158.8 145.4 A 6.62 TSP-EO 220.75 + 146.9 161.1 158.3169.7 164.2 189.0 B 8.28

Example 4-2

Table 22 shows the loading level of TSP Ethoxylate of the presentinvention on F/T Stability of low VOC Paints.

TABLE 22 Loading Level of TSP-EO on Freeze- Thaw Stability of Low VOCSemigloss Paints TSP-EO (wt % Viscosity (Krebs Units, KU) based on dryInitial polymer weight) Vis. 1 cycle 2 cycles 3 cycles 4 cycles 5 cycles0 115.4 Gel — — — — 0.86 114.6 126.3 gel — — — 1.30 101.4 128.7 >140 gel— — 1.71 110.5 109 113.6 120.2 129.3 gel 2.57 106.6 102.3 103.8 103.8106.9 109.2 3.43 105.1 102.3 102.6 102.6 103.8 105.8 4.29 104.1 100.9101.4 101.2 102.3 104.1 8.00 93.2 97.5 98.5 98.8 100.3 101.2

Referring to Table 23, F/T stability is observed at or above about 1.3%based on the total polymer weight using the TSP-EO of the presentinvention.

TABLE 23 Loading Level of TSP-EO on Freeze- Thaw Stability of Low VOCFlat Paints TSP-EO (wt % Viscosity (Krebs Units, KU) based on dryInitial polymer weight) Vis. 1 cycle 2 cycles 3 cycles 4 cycles 5 cycles280.5 + 0.00 104.8 gel — — — — 280.5 + 0.56 102.4 108.6 116.6 122 131.4136 280.5 + 1.11 100.4 104.2 108.5 111.8 117.5 120.5 280.5 + 1.67 98.5100.1 102.4 104 106.7 109.6 280.5 + 2.22 96 97.2 98.5 99.7 102 104.2280.5 + 2.78 95.5 95.4 96.4 97.3 99.2 100.3

Example 4-3

TSP ethoxylates in varying amounts were added to low or zero VOCcommercial paints and tested for freeze thaw stability. Table 24 showsthe effects of TSP-EO of the present invention on F/T Stability ofvarious Low/Zero VOC Commercial Paints. The control contained no TSPethoxylated surfactant (TSP-EO).

TABLE 24 Freeze-Thaw Stability Low/Zero Viscosity, (KU) after 1, 2, 3,4, and 5 cycles VOC Starting Viscosity 10.0 lbs/100 gals 15.0 lbs/100gals Commercial 10.0 lbs/ 15.0 lbs/ of added F/T of added Paints Control100 gals 100 gals Control additive F/T additive Paint 1 112.1 91.2 88.3130/>140/140.0/ 101.9/116.2/123.1/ 88.3/98.3/121.8/ (advertised as 0139.4/139.2 102.2/102.6 103.8/100.7 VOC) Paint 2 109.2 98.5 95 gel/—105.2/106.5/102.9/ 95.6/95.7/93.8/ (advertised as 100.9/100.0 94.3/94.437 g/L) Paint 3 102.3 80.8 73.8 gel/— 91/107.8/108.0/ 85.9/99.8/99.9/(advertised as 108.6/111.4 99.2/100.0 0 VOC) Paint 4 99.9 97.6 101.1gel/— 123.8/gel/— 126.4/gel/— (advertised as Low VOC) Paint 5 108.4 86.680.8 gel/— 120.1/gel/— 106.9/89.4/115.2/ (advertised as 41 g/L)117.1/118.2 Paint 6 111.5 93.7 87.2 gel/— gel/— 98.6/107.6/99.4/(advertised as 0 100.4/99.5 VOC) Paint 7 105.5 87 85 gel/—96.5/114.5/107.7/ 92.4/109.4/103.8/ (advertised as 0 106.9/107.3106.2/104.9 VOC) Paint 8 102.7 84 79.3 121.1/gel/— 86.3/97.7/97.1/91.3/82.8/96.1/85.9/ (advertised as 0 92.2 88.0/88.4 VOC) Paint 9 119.4 89.887.6 gel/— 126.2/gel/— 127.1/gel/— (advertised as 50 g/L) Paint 10 112.588.7 83.2 gel/— 93.7/93.7/92.0/94.1/ 87.8/93.5/86.3/ (advertised as 50g/L) 91.0 86.6/86.7 Paint 11 107.2 91 84.8 gel/— gel/— 102.2/98.4/95.0/(advertised as 50 g/L) 95.6/94.5 Paint 12 120.6 95.1 84.3 gel/—114.3/gel/— 94.4/109.4/102.0/ (advertised as 50 g/L) 102.5/102.5

Example 4-5

Open time—Tables 25 and 26 show the effects of TSP Ethoxylate nonionicsurfactants on “open time” of Low VOC Paints and the Effects of TSPEthoxylate Anionic Surfactants on “open time” of Low VOC Paints,respectively. Open time is generally understood to be the interval,after the paint is applied, during which it can be blended withadditional painted regions (at the “wet edge”). Open time refers to theamount of time a newly-applied layer of paint remains workable beforebrush strokes and other signs of manipulation become visible in driedfilms. The method for measuring Open Time is generally as follows: a 10mils film is drawn down on a piece of black scrub test paper. The paintfilm is then cross-hatched in two-inch intervals with the eraser end ofa pencil. The first cross hatch then brushed over in one direction 15times; this is then repeated in two-minute intervals for each successivecross-hatch. After 48 hrs, the dry films are examined for the earliesttimes at which traces of cross-hatch at discernable. This is performedunder constant humidity, room temp. It is desirable for paintformulations to have an open time of greater than 4 minutes, typically,greater than 6 minutes. The amount of reagent (both nonionic surfactantsand anionic surfactants) varied from about 2.5 grams surfactant to about4.25 grams surfactant per 256 grams of paint.

TABLE 25 Reagent open time (Nonionic starting (minutes) Surfactants)viscosity (KU) sample Control TSP-EO #1 89.9 >14 4 TSP-EO #2 85 >14 4TSP-EO #3 82 14 2 to 4 TSP-EO #4 81.2 >14 4 TSP-EO #5 89.9 4 2

TABLE 26 Reagent open time (Anionic starting (minutes) Surfactants)viscosity (KU) sample Control TSP-EO TEA 83.3   14 2 to 4 salt TSP-EO83.5 8 to 10 2 Ammonium Sulfate Salt TSP-EO 86.4 8 to 12 2 PotassiumSalt 1 TSP-EO-PO 83.5 >14 4

Referring back to Tables 25 and 26, it is observed that open timeincreased significantly when utilizing either the non-ionic TSPadditives or anionic TSP additives, respectively.

In the above detailed description, preferred embodiments are describedin detail to enable practice of the invention. Although the invention isdescribed with reference to these specific preferred embodiments, itwill be understood that the invention is not limited to these preferredembodiments. But to the contrary, the invention includes numerousalternatives, modifications and equivalents as will become apparent fromconsideration of the following detailed description. It is understoodthat upon reading the above description of the present invention, oneskilled in the art could make changes and variations therefrom. Thesechanges and variations are included in the spirit and scope of thefollowing appended claims.

1. A low VOC latex coating composition comprising: (a) at least onelatex polymer; (b) at least one pigment; (c) water; and (d) an additivepresent in an amount effective to impart freeze-thaw stability to thecomposition, the additive having structural formula IIA:

wherein R₁, R₂ and R₃ are independently selected from the groupconsisting of: butyl, tert-butyl, isobutyl,

wherein X is a divalent hydrocarbon radical comprising a linear orbranched alkylene radical having from about 2 to 8 carbon atoms; whereinn is an integer of from 1 to 100; wherein R₅ is selected from the groupconsisting of —OH, —OCH₃, —OC₂H₅, —OC₃H₇, —OC₄H₉, —OC₅H₁₁, —OC₆H₁₃, —Cl,—Br, —CN, Phosphonate (—PO₃ ⁻M⁺), Phosphate (—PO₄ ⁻M⁴), Sulfate (—SO₄⁻M⁺), Sulfonate (—SO₃ ⁻M⁺), carboxylate (COO⁻M⁺), a nonionic group, anda quaternary ammonium ion, wherein M⁺ is a cation; further wherein theadditive is present in an amount greater than about 1.3% by weight ofthe polymer.
 2. The latex coating composition of claim 1 wherein n is aninteger of from about 3 to about
 80. 3. The latex coating composition ofclaim 1 wherein n is an integer of from about 10 to about
 50. 4. Thelatex coating composition of claim 1 wherein n is an integer of fromabout 20 to about
 50. 5. The latex coating composition of claim 1wherein the additive is present in an amount greater than about 1.6% byweight of the polymer.
 6. The latex coating composition according toclaim 1, wherein the additive is present in an amount greater than about2% by weight of the polymer.
 7. The latex coating composition accordingto claim 1 , wherein the additive is present in an amount greater thanabout 7.5% by weight of the polymer.
 8. The latex coating compositionaccording to claim 1, wherein the additive is present in an amountgreater than about 8% by weight of the polymer.
 9. The latex coatingcomposition according to claim 1, wherein the additive is present in anamount greater than about 10% by weight of the polymer.
 10. The latexcoating composition according to claim 1, wherein the additive ispresent in an amount greater than about 20% by weight of the polymer.11. The latex coating composition of claim 1 wherein the polymer has aglass transition temperature (Tg) of between about −15° C. and about 12°C.
 12. The latex coating composition of claim 1 wherein the polymer hasa glass transition temperature (Tg) of between about −5° C. and about 5°C.
 13. The latex coating composition of claim 1 wherein the polymer hasa glass transition temperature (Tg) of between about −5° C. and about 0°C.
 14. The latex coating composition of claim 1 wherein the polymer hasa mean particle size of less than about 200 nm.
 15. The latex coatingcomposition of claim 1 wherein the polymer has a mean particle size ofless than about 190 nm.
 16. The latex coating composition of claim 1wherein the polymer has a mean particle size of less than about 175 nm.17. The latex coating composition of claim 1 wherein the coatingcomposition is characterized by an open time of greater than about 4minutes.
 18. The latex coating composition of claim 1 wherein the latexcoating composition is characterized by an open time of greater thanabout 6 minutes.
 19. The latex coating composition of claim 1 whereinthe latex coating composition is characterized by an open time ofgreater than about 12 minutes.
 20. A low VOC latex coating composition,comprising: (a) at least one latex polymer; (b) at least one pigment;(c) wafer; and (d) an additive present in an amount effective to impartfreeze-thaw stability to the composition, the additive having structuralformula:

wherein, n is an integer of from 1 to 100, and R₅ is selected from thegroup consisting of —OH, —OCH₃, —OC₂H₅, —OC₃H₇, —OC₅H₁₁, —OC₆H₁₃,—OC₄H₉, —Cl, —Br, —CN, Phosphonate (—PO₃ ⁻M⁺), Phosphate (—PO₄ ⁻M⁺),Sulfate (—SO₄ ⁻ M⁺), Sulfonate (—SO₃ ⁻M⁺), carboxylate (COO⁻M⁺), anonionic group; and a quaternary ammonium ion, wherein M⁺ is a cation.21. The latex coating composition of claim 20 wherein n is an integer offrom about 3 to about
 80. 22. The latex coating composition of claim 20wherein n is an integer of from about 10 to about
 50. 23. The latexcoating composition of claim 20 wherein n is an integer of from about 20to about
 50. 24. The latex coating composition of claim 20 wherein theadditive is present in an amount greater than about 1.3% by weight ofthe polymer.
 25. The latex coating composition of claim 20 wherein theadditive is present in an amount greater than about 1.6% by weight ofthe polymer.
 26. The latex coating composition of claim 20 wherein theadditive is present in an amount greater than about 2% by weight of thepolymer.
 27. The latex coating composition according to claim 20,wherein the additive is present in an amount greater than about 4% byweight of the polymer.
 28. The latex coating composition according toclaim 20, wherein the additive is present in an amount greater thanabout 7.5% by weight of the polymer.
 29. The latex coating compositionaccording to claim 20, wherein the additive is present in an amountgreater than about 8% by weight of the polymer.
 30. The latex coatingcomposition according to claim 20, wherein the additive is present in anamount greater than about 10% by weight of the polymer.
 31. The latexcoating composition according to claim 20, wherein the additive ispresent in an amount greater than about 20% by weight of the polymer.32. The latex coating composition of claim 20 wherein the polymer has aglass transition temperature (Tg) of between about −15° C. and about 12°C.
 33. The latex coating composition of claim 20 wherein the polymer hasa glass transition temperature (Tg) of between about −5° C. and about 5°C.
 34. The latex coating composition of claim 20 wherein the polymer hasa glass transition temperature (Tg) of between about −5° C. and about 0°C.
 35. The latex coating composition of claim 20 wherein the polymer hasa mean particle size of less than about 200 nm.
 36. The latex coatingcomposition of claim 20 wherein the polymer has a mean particle size ofless than about 190 nm.
 37. The latex coating composition of claim 20wherein the polymer has a mean particle size of less than about 175 nm.38. The latex coating composition of claim 20 wherein the latex coatingcomposition is characterized by an open time of greater than about 4minutes.
 39. The latex coating composition of claim 20, wherein thelatex coating, composition is characterized by an open time of greaterthan about 6 minutes.
 40. The latex coating composition of claim 20wherein the latex coating composition is characterized by an open timeof greater than about 12 minutes.